doc: Update rfc2629.dtd, use local copy, fix error, and fix warning

- I get this warning when building the docs:
WARNING: No DTD given, defaulting to
/usr/lib/python3.7/site-packages/xml2rfc/templates/rfc2629.dtd

- Patching Makefile.am to use the local DTD gives the below error:
ERROR: Unable to validate the XML document: protocol-binary.full
protocol-binary.full: Line 2: Value "trust200902" for attribute ipr of
rfc is not among the enumerated set

- This commit suggests that you prefer to use a local copy of the DTD.
    commit fe2629fd3fcdbde49f4016635866bd3488be88b0
    Author: Steve Wills <steve@mouf.net>
    Date:   Wed Jul 23 19:21:40 2014 +0000

        keep local copies of dtd and use it
        This commit ensures we don't rely on and external site for the docs
        to build.
        If that site were to go away, we wouldn't be able to build docs.

- Hence, update the DTD too.

2 files changed, 27 insertions, 16 deletions

diff --git a/doc/Makefile.am b/doc/Makefile.am
index daee615..94278c0 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -20,9 +20,10 @@ MOSTLYCLEANFILES += $(SPECIFICATIONS)
 endif
 
 RFC2629_XSL = $(srcdir)/xml2rfc/rfc2629-noinc.xsl
+RFC2629_DTD = $(srcdir)/xml2rfc/rfc2629.dtd
 
-%.txt: %.full
-	@XML2RFC@ -c $(builddir) $< $@
+%.txt: %.full $(RFC2629_DTD)
+	@XML2RFC@ -d $(RFC2629_DTD) -c $(builddir) $< $@
 
 %.full: %.xml $(RFC2629_XSL)
 	@XSLTPROC@ --nonet $(RFC2629_XSL) $< > $@
diff --git a/doc/xml2rfc/rfc2629.dtd b/doc/xml2rfc/rfc2629.dtd
index bc30260..436cd87 100644
--- a/doc/xml2rfc/rfc2629.dtd
+++ b/doc/xml2rfc/rfc2629.dtd
@@ -1,5 +1,5 @@
 <!--
-  revised DTD for the RFC document series, draft of 2007-03-29
+  revised DTD for the RFC document series, draft of 2009-10-06
   -->
 
 
@@ -83,7 +83,7 @@
 
 <!ENTITY % TEXT       "#PCDATA">
 
-<!ENTITY   rfc.number "XXXX">
+<!ENTITY   rfc.number SYSTEM "internal:/rfc.number">
 
 
 <!--
@@ -104,14 +104,18 @@
           updates     %NUMBERS;          ""
           category    (std|bcp|info|exp|historic)
                                          #IMPLIED
+          consensus   (no|yes)           #IMPLIED
           seriesNo    %NUMBER;           #IMPLIED
           ipr         (full2026|noDerivativeWorks2026|none
                       |full3667|noModification3667|noDerivatives3667
-                      |full3978|noModification3978|noDerivatives3978)
+                      |full3978|noModification3978|noDerivatives3978
+                      |trust200811|noModificationTrust200811|noDerivativesTrust200811
+                      |trust200902|noModificationTrust200902|noDerivativesTrust200902
+                      |pre5378Trust200902)
                                          #IMPLIED
           iprExtract  IDREF              #IMPLIED
           submissionType
-                      (IETF|independent) "IETF"
+                      (IETF|IAB|IRTF|independent) "IETF"
           docName     %ATEXT;            #IMPLIED
           xml:lang    %ATEXT;            "en">
 
@@ -127,9 +131,9 @@
 <!-- the "abbrev" attribute is used for headers, etc. -->
 <!ELEMENT title       (%CTEXT;)>
 <!ATTLIST title
-          abbrev      %ATEXT;            #IMPLIED>
+          abbrev      %ATEXT;            #IMPLIED> 
 
-<!ELEMENT author      (organization,address?)>
+<!ELEMENT author      (organization?,address?)>
 <!ATTLIST author
           initials    %ATEXT;            #IMPLIED
           surname     %ATEXT;            #IMPLIED
@@ -139,8 +143,8 @@
 <!ELEMENT organization
                       (%CTEXT;)>
 <!ATTLIST organization
-          abbrev      %ATEXT;            #IMPLIED>
-
+          abbrev      %ATEXT;            #IMPLIED> 
+ 
 <!ELEMENT address     (postal?,phone?,facsimile?,email?,uri?)>
 
 <!-- this content model should be more strict:
@@ -179,17 +183,17 @@
   -->
 
 
-<!-- later on, may be (section+,appendix*,section*) -->
 <!ELEMENT middle      (section+)>
 
 <!ELEMENT section     ((t|figure|texttable|iref)*,section*)>
 <!ATTLIST section
           anchor      ID                 #IMPLIED
           title       %ATEXT;            #REQUIRED
+	  numbered    (yes|no)		 #IMPLIED
           toc         (include|exclude|default)
                                          "default">
 
-<!--
+<!-- use of <appendix/> is deprecated...
 <!ELEMENT appendix    ((t|figure|texttable|iref)*,appendix*)>
 <!ATTLIST appendix
           anchor      ID                 #IMPLIED
@@ -204,7 +208,7 @@
           anchor      ID                 #IMPLIED
           hangText    %ATEXT;            #IMPLIED>
 
-<!-- the value of the style attribute is inherited from the closest
+<!-- the value of the style attribute is inherited from the closest 
      parent -->
 <!ELEMENT list        (t+)>
 <!ATTLIST list
@@ -236,6 +240,7 @@
 
 <!ELEMENT spanx       (%CTEXT;)>
 <!ATTLIST spanx
+          xml:space   (default|preserve) "preserve"
           style       %ATEXT;            "emph">
 
 <!ELEMENT vspace      EMPTY>
@@ -246,6 +251,7 @@
 <!ATTLIST figure
           anchor      ID                 #IMPLIED
           title       %ATEXT;            ""
+          suppress-title (true|false)    "false"
           src         %URI;              #IMPLIED
           align       (left|center|right) "left"
           alt         %ATEXT;            ""
@@ -265,14 +271,17 @@
           height      %ATEXT;            "">
 
 <!ELEMENT postamble   (%TEXT;|xref|eref|iref|cref|spanx)*>
-
+    
 <!ELEMENT texttable   (preamble?,ttcol+,c*,postamble?)>
 <!ATTLIST texttable
           anchor      ID                 #IMPLIED
-          title       %ATEXT;            "">
+          title       %ATEXT;            ""
+          suppress-title (true|false)    "false"
+          align       (left|center|right) "center"
+          style       (all|none|headers|full) "full">
 <!ELEMENT ttcol       (%CTEXT;)>
 <!ATTLIST ttcol
-          width       %ATEXT;           #IMPLIED
+          width       %ATEXT;            #IMPLIED
           align       (left|center|right) "left">
 <!ELEMENT c           (%TEXT;|xref|eref|iref|cref|spanx)*>
 
@@ -290,6 +299,7 @@
           title       %ATEXT;            "References">
 <!ELEMENT reference   (front,seriesInfo*,format*,annotation*)>
 <!ATTLIST reference
+	  quote-title (true|false)	 "true"
           anchor      ID                 #IMPLIED
           target      %URI;              #IMPLIED>
 <!ELEMENT seriesInfo  EMPTY>