Allow non-master branches to get cached.

We allow caching of non-master packagers (el6 for example).
This covers the centos packaging case.
Add Centos puppet support.

For Centos we install puppet 2.7 from puppetlabs. This
matches what we currently use for Fedora 18.
Remove pre_package sections (unused).
Make fog/torpedo build_packages tasks generic.
Centos build updates (fog/torpedo, etc).

Misc build updates for Centos.
Update examples to use build:packages.

Replace the individual package build tasks with the new consolidated
build:packages task which uses config files for its configuration.
Add new build:packages task.
Nail quantumclient right before rename.
Save SRPMS in addition to RPMS.

We want to cache SRPMS too.
Add tasks to build oslo.sphinx.
Add neutronclient builds.

For now adding neutronclient to the misc builds task as well.
Once we update SmokeStack to support neutronclient we'll move it
there.
Fix lsb install on RHEL/Centos.
Nail excon at 0.25.1.
Merge remote branch 'upstream/master'
Cleanup some unused xen tasks.
Updates to use new package caching servers.

Our new package caching CGI script supports multi-distro. This update
adds a new distro_name URL param to pass that along when posting/using
the cache. Also, includes HTTP auth support for POSTing to the cache.
Disable quantumclient builds for now.
Recent builds of PBR seem to be missing migrate.cfg again.
Add distro name check to caching task.

Adds an extra check to ensure the incorrect DISTRO_NAME
isn't passed into the caching task.
Merge branch 'upstream'