Fix error in initializing local master and develop

For some versions of git (eg on quantal),

    git checkout BRANCH

doesn't work if BRANCH doesn't exist yet. It's necessary to use

    git checkout -t origin/BRANCH

instead.

Change-Id: Ib99dedaf1a4ec38f57ca697656c90de09f2cb455
Prune old remote branches when re-ininitializing repos

Change-Id: I96f5f97ad354ea0412653970443f7983efa9a09f
Enable the user to specify branches with wildcards

Change-Id: If8ad3ff9f00bcb141f5ad8bc067e237a000dbe7e
Add release/* and support/* to default branches

Change-Id: I734b7dabaec6e7164b95ac01e073d0d81afeafe9