doc: rename diff.texi to diffutils.texi

This makes the .texi basename the same as the package name,
which is consistent with most other GNU packages.
* doc/diffutils.texi: Rename from...
* doc/diff.texi: ...removed.
* doc/Makefile.am (info_TEXINFOS): Reflect name change.
(diffutils_TEXINFOS): Likewise.
* cfg.mk (gendocs_options_): Remove this customization.  It is no
longer needed, now that the .texi name matches that of the package.
* man/Makefile.am ($(dist_man1_MANS)): Remove now-unnecessary sed
filter.
* README: Update references to diffutils.texi etc. here, too.
* .gitignore: Update here, too.
Suggested by Karl Berry.

2 files changed, 9 insertions, 9 deletions

diff --git a/doc/Makefile.am b/doc/Makefile.am
index 99287fa..73e8a37 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -17,7 +17,7 @@
 
 AM_MAKEINFOFLAGS = --no-split
 
-info_TEXINFOS = diff.texi
-diff_TEXINFOS = fdl.texi
+info_TEXINFOS = diffutils.texi
+diffutils_TEXINFOS = fdl.texi
 
 EXTRA_DIST = diagmeet.note
diff --git a/doc/diff.texi b/doc/diffutils.texi
index b9e23dc..4abc3fe 100644
--- a/doc/diff.texi
+++ b/doc/diffutils.texi
@@ -1,6 +1,6 @@
 \input texinfo @c -*-texinfo-*-
 @comment %**start of header
-@setfilename diff.info
+@setfilename diffutils.info
 @include version.texi
 @settitle Comparing and Merging Files
 @syncodeindex vr cp
@@ -36,16 +36,16 @@ supports it in developing GNU and promoting software freedom.''
 @c first dircategory.  Put this one first, as it is more useful in practice.
 @dircategory Individual utilities
 @direntry
-* cmp: (diff)Invoking cmp.                      Compare 2 files byte by byte.
-* diff: (diff)Invoking diff.                    Compare 2 files line by line.
-* diff3: (diff)Invoking diff3.                  Compare 3 files line by line.
-* patch: (diff)Invoking patch.                  Apply a patch to a file.
-* sdiff: (diff)Invoking sdiff.                  Merge 2 files side-by-side.
+* cmp: (diffutils)Invoking cmp.                 Compare 2 files byte by byte.
+* diff: (diffutils)Invoking diff.               Compare 2 files line by line.
+* diff3: (diffutils)Invoking diff3.             Compare 3 files line by line.
+* patch: (diffutils)Invoking patch.             Apply a patch to a file.
+* sdiff: (diffutils)Invoking sdiff.             Merge 2 files side-by-side.
 @end direntry
 
 @dircategory Text creation and manipulation
 @direntry
-* Diff: (diff).                 Comparing and merging files.
+* Diffutils: (diffutils).       Comparing and merging files.
 @end direntry
 
 @titlepage