remote-bzr: include authors field in pushed commits

Tests-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
remote-hg: fix parsing of custom committer

Other tools use the 'committer' extra field differently, so let's make
the parsing more reliable and don't assume it's in a certain format.

Reported-by: Kevin Cox <kevincox@kevincox.ca>
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Git v1.9.1+fc2

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Merge tag 'v1.9.1+fc2' into travis

Git 1.9.1+fc2

* tag 'v1.9.1+fc2':
  Git v1.9.1+fc2
  remote-hg: fix parsing of custom committer
  remote-bzr: include authors field in pushed commits