Fix argument names it git.branch.
Install sudo if not installed.
Merge branch 'sudo'.
Merge remote-tracking branch 'origin'
Factor out creating service users to braid.users.
Add support for installing packages on fedora.
Add amptrac config.
Make users.createService more configurable.

This is for installing buildslaves.
Use specified python for install twisted.
Fix the permissions of authorized_keys in users.uploadKeys.