versioncontrol: add two more tests for diffs, one testing a filtered out group, the other testing a full context diff.
versioncontrol: add two more tests for diffs, one testing a filtered out group, the other testing a full context diff.

git-svn-id: f68c6b3b1dcd5d00a2560c384475aaef3bc99487@10573 af82e41b-90c4-0310-8c96-b1721e28e2e2

exocad/exotrac,exocad/exotrac,exocad/exotrac,exocad/exotrac