Adapt version control's cache to PostgreSQL 8.3. A few explicit casts of the revision to a str were missing.
Adapt version control's cache to PostgreSQL 8.3. A few explicit casts of the revision to a str were missing.

Closes #6274.

git-svn-id: 0d96b0c1a6983ccc08b3732614f4d6bfcf9cbb42@6415 af82e41b-90c4-0310-8c96-b1721e28e2e2

rbaumg/trac,rbaumg/trac,rbaumg/trac,rbaumg/trac