Mentioned more files in tn0011.txt that need version updating, and made it more clear which ones need to be changed manually. Modified inc_release to update docs/readme.txt and changed the version references in the readme.txt to 2.9.3. Also changed two references to the month of release from July to December.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@69920 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775