fix execution of git merge-base and remove extraneous newlines

commands.getoutput was producing an error message "'{' is not recognized as an internal or external command," I assume it was trying to run the command in a subshell using sh syntax, which is not valid in a cmd.exe shell.

The whole script should probably be converted to 'subprocess'

Also `if baserev != oldrev:` was failing due to the newline printed after the revision number by the command 'git merge-base'.
remove unused method per @benallard's suggestion
Merge pull request #1331 from djmitche/remove-mock-method

remove unused method per @benallard's suggestion
Revert "IRCContact use the DATA API"
Revert "Revert "Merge pull request #1323 from delanne/IRCContact""

This reverts commit c203010282e3651673f98540b88c7302c7b71082.
Merge pull request #1333 from delanne/FixBadRevert

Revert "Revert "Merge pull request #1323 from delanne/IRCContact""
Merge pull request #1332 from delanne/revert-1323-IRCContact

Revert "IRCContact use the DATA API"
IRCContact consume 2 events:

    ('builders', None, 'builds', None, 'new') => A build is started
    ('builders', None, 'builds', None, 'finished') => A build is finished

When we will be able to get the list of changes for a build, the IRCContact must be updated.
Fix sa2ajj's comment
Fix Doc for Dependent Scheduler
Should fix sa2ajj's comment
Merge pull request #1336 from delanne/DocFix

Fix Doc for Dependent Scheduler
Merge pull request #1310 from socantre/patch-1

fix execution of merge-base and remove extraneous newlines
Merge pull request #1335 from delanne/IRCContact

IRCContact use the DATA API
Generate the missing indices.
Merge pull request #1339 from benallard/patch-1

Generate the missing indices
The slave property of the slave was renamed conn in 6885d46a3e9
Make AbstractLatentBuildSlave.sendBuilderList similar to BuildSlave.sendBuilderList
Move the disconnect hack to the protocol layer
Merge pull request #1341 from benallard/fix-abstractlatentbuildslave

Fix AbstractLatentBuildslave

Fixes ticket:2970