Bug#683480: add a way detect the version number automatically

[jidanni at jidanni.org]

Package: devscripts
Version: 2.12.1
Severity: wishlist
File: /usr/share/man/man1/bts.1.gz

       found bug [version]
           Indicate that a bug was found to exist in a particular package
           version.

Mention on the man page what happens if you don't give a version number,
and the point thereof.

$ bts found 99999999
bts: found has no version number, but sending to the BTS anyway

Also give a way to detect the version number automatically,
sort of like aptitude forbid-version does.