Update documentation about bugs reporting and new releases notification

* README.md (Download): Add link to BDWGC Download page on GitHub.
* README.md (Overview): Change link (for the further information) from
hboehm.info/gc to doc/overview.html.
* README.md (Bugs): Remove information about bugs reporting from this
section.
* README.md (Feedback, Contribution, Questions and Notifications): New
section.
* configure.ac (AC_INIT): Change URI for reporting bugs.
* doc/gc.man (SEE ALSO): Add link to the BDWGC main page on GitHub.
* doc/gcdescr.html: Remove information how to provide feedback.
* doc/overview.html (Contacts and Mailing List): Update information
(recommend use of GitHub and Stack Overflow, provide links to the
archives of the former mailing lists).

1 files changed, 24 insertions, 4 deletions

diff --git a/README.md b/README.md
index ce11b7b7..0e57c741 100644
--- a/README.md
+++ b/README.md
@@ -12,6 +12,7 @@ collector for C and C++.
 ## Download
 
 You might find a more recent/stable version on the
+[Download](https://github.com/ivmai/bdwgc/wiki/Download) page, or
 [BDWGC site](http://www.hboehm.info/gc/).
 
 Also, the latest bug fixes and new features are available in the
@@ -73,7 +74,7 @@ collector.  (See doc/README.cords and H.-J. Boehm, R. Atkinson, and M. Plass,
 in Xerox Cedar, or the "rope" package in the SGI STL or the g++ distribution.)
 
 Further collector documentation can be found
-[here](http://www.hboehm.info/gc/).
+in [overview.html](doc/overview.html).
 
 
 ## General Description
@@ -547,9 +548,28 @@ per MB of accessible memory that needs to be scanned and processor.
 Your mileage may vary.)  The incremental/generational collection facility
 may help in some cases.
 
-Please address bug reports [here](mailto:bdwgc@lists.opendylan.org).
-If you are contemplating a major addition, you might also send mail to ask
-whether it's already been done (or whether we tried and discarded it).
+
+## Feedback, Contribution, Questions and Notifications
+
+Please address bug reports and new feature ideas to
+[GitHub issues](https://github.com/ivmai/bdwgc/issues).  Before the
+submission please check that it has not been done yet by someone else.
+
+If you want to contribute, submit
+a [pull request](https://github.com/ivmai/bdwgc/pulls) to GitHub.
+
+If you need help, use
+[Stack Overflow](https://stackoverflow.com/questions/tagged/boehm-gc).
+Older technical discussions are also available in
+[bdwgc mailing list archive](https://github.com/ivmai/bdwgc/files/1038163/bdwgc-mailing-list-archive-2017_04.tar.gz).
+
+To get new release announcements, subscribe to
+[RSS feed](https://github.com/ivmai/bdwgc/releases.atom).
+(To receive the notifications by email, a 3rd-party free service like
+[IFTTT RSS Feed](https://ifttt.com/feed) can be setup.)
+To be notified on all issues, please
+[watch](https://github.com/ivmai/bdwgc/watchers) the project on
+GitHub.
 
 
 ## Copyright & Warranty