Only try to work out the previous version number if the master feed file actually...
commitef0b0bf156c6a346e3c9bb26bdf25eb8cdb148df
authorThomas Leonard <talex5@gmail.com>
Sun, 18 Nov 2007 18:03:00 +0000 (18 18:03 +0000)
committerThomas Leonard <talex5@gmail.com>
Sun, 18 Nov 2007 18:04:14 +0000 (18 18:04 +0000)
treeefbbfc7fd2a7113faf26d871c5118f69ff54c603
parenta2d52f84e14621dc1da2c90e3c61c07782be8abe
Only try to work out the previous version number if the master feed file actually exists.

Also, generate the log correctly when no previous version can be found.
release.py
scm.py