Normalize Gemfile & pin tests to rspec < 2.99

Pin to rspec < 2.99 until rspec-puppet officially supports rspec 3.x.
This is to avoid warnings due to deprecated matchers in the
rspec-puppet gem.

This change is also intended to normalize the Gemfile for all stackforge
puppet modules.  This should facilitate pinning gem versions when
releasing new stable branches, since the same diff can be used for all
repos.

Conflicts:
  Gemfile

Change-Id: I08dfd8e6a07d60e2421045a0f9d729cc9c26899c
Partial-Bug: #1326034
(cherry picked from commit 6e38374e16276619161f7bddd185155493c5d908)
Introduce glance:config to manage custom options

This glance::config is aim to use glance_config resources
to manage custom configurations in glance config files.

This will make end user easy to add their own custom options
in Hiera data.

Fully implements blueprint glance-custom-config

(cherry-picked from 11f5e87a0fe9f9adefcc2b814c4d26950f7dd760)
Change-Id: Idc47b6bda3ea38e582501278f82c9c6841b8cdf0