bugreports: Replace old Bugzilla references

We use Trac since a while now.



git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@37252 b3059339-0415-0410-9bf9-f77b7e298cf2
release-howto: Rewrite instructions from Bugzilla to Trac



git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@37253 b3059339-0415-0410-9bf9-f77b7e298cf2
vd_ffmpeg: Rewrite ticket reference in comment

Omit the issue tracking software's name. Despite the migration from
Bugzilla to Trac we were able to keep the ticket numbers.



git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@37254 b3059339-0415-0410-9bf9-f77b7e298cf2