Merge pull request #1657 from aabes/master

ignore reloadable directories if they don't exist in the source BC
Add pull-requests checkout, and refactor pull-requests switch to use it.
Assume that rebase worked if it passes without issue.
Refactor remote syncing a bit to make it easier to add other repos.
Make sure everything knows where the cache is.
Get rid of annoying error message

The following error message appears multiple times when running
`./dev setup-unit-tests --update-gem-cache`:

  crowbar/./parse_yml.rb:7: undefined method `[]' for nil:NilClass (NoMethodError)
    from crowbar/./parse_yml.rb:6:in `each'
    from crowbar/./parse_yml.rb:6

This patch prevents that.
Move the Gemfile instead of copying it.

This keeps bundle from complaining.
Fix up run_unit_tests to run various important things under bundle exec.
Merge pull request #1659 from jamestyj/jamestyj-parse-yml

Merged by devtool for VictorLowther
Update iso for 12.04 to 12.04.1
Clean gemfile to allow the parent gemfile to be used.
rcov should ignore the config directory and not all files with config.
Merge pull request #1663 from galthaus/master

Merged by devtool for cloudedge