2.6 changelog gen/version/root dir cleanup (#40421)

* patched in changelog gen stuff from stable-2.5
* Makefile updates
* release.py as single-source-of-truth
* Remove obsolete ansible-core-sitemap.xml file.
* Move ROADMAP.rst into README.rst.
* dynamic rpm changelog, zap old deb/rpm changelogs
* fix changelog in MANIFEST.in
* Remove obsolete hacking/update.sh script.
* Remove ref to deleted authors script.
* Remove ref to removed module-formatter script.
* Update headings to match script names.
* MANIFEST.in cleanup
* removed RELEASES.txt and versions.yml
* removed obsolete release generation playbook/bits (not used since 2.5)
* misc Makefile cleanup
* speculative changes to DEB versioning
* allow override of DEB_VERSION/DEB_RELEASE

hacking/ticket_stubs/file_under_another_project.md

@@ -0,0 +1,23 @@
+Should This Be Filed Elsewhere?
+===============================
+
+Hi!
+
+Thanks very much for your interest in Ansible.  It sincerely means a lot to us. 
+
+This appears to be something that should be filed against another project or bug tracker, and let us explain our reasons for thinking this:
+
+   * FILL IN
+
+If you can stop by the tracker or forum for one of those projects, we'd appreciate it.  
+
+Should you still wish to discuss things further, or if you disagree with our thought process, please stop by one of our two mailing lists:
+
+  * https://groups.google.com/forum/#!forum/ansible-project
+  * https://groups.google.com/forum/#!forum/ansible-devel
+
+We'd be happy to discuss things.
+
+Thank you once again!
+
+