Merge branch 'setup'

Add scripts/gitsetup/ directory using subtree merge from
the general GitSetup repository "setup" branch.

* setup:
  Add 'git-gerrit-push' script
  Tell Git how to check GitSetup config files
  setup-stage: Allow 'url' without 'pushurl'
  setup-gerrit: Allow ssh-only repo URLs
  setup-stage: Optionally reconfigure topic stage
  Exclude from source archives files specific to Git work tree
  Add README instructions and sample configuration
  Add 'setup-ssh' script to configure ssh push access
  Add 'setup-stage' script to configure topic stage remote
  Add 'setup-gerrit' script to configure Gerrit access
  Add 'setup-hooks' script to install local hooks
  Add 'setup-user' script to configure authorship information
  Add 'tips' script to suggest local configuration
  Add LICENSE and NOTICE
Added git setup config file
Added helper script to setup developement environment