Add script verify and multi-scm script verify

* Add example templates for doing verify jobs that use a script instead of
  maven

* Add new 'git-extra-project' macro for doing git checkouts that are not
  the base project checkout. These _must_ be checked out to a specified
  subdirectory

* Add example template that does two git checkouts

Change-Id: I522da87d591ee819a8fd67c22e25906b851a581e
Signed-off-by: Andrew Grimberg <agrimberg@linuxfoundation.org>
2 files changed