gitbuilder: adding a Hadoop gitbuilder

Code to automatically build cephfs/branch-1.0
branches of hadoop-common.

Signed-off-by: Joe Buck <jbbuck@gmail.com>
Parameterizing the branches-local script to use in _gitbuilder()
fabfile.py: slight fix
Signed-off-by: Joe Buck <jbbuck@gmail.com>
Parameterizing the branch to bundle.
Signed-off-by: Joe Buck <jbbuck@gmail.com>