[rdo-list] Adding backwards compatible tripleo-heat-templates packaging

I've posted a WIP patch[1] based on what we've done in the downstream OSP releases with tripleo-heat-templates to provide backwards compatible heat templates for managing older versions. The base requirements are: * Package the latest tripleo-heat-templates from the previous release (in this case mitaka) * Must be installable side-by-side with the the current version heat-templates * A single srpm if at all possible The patch essentially mimics what has been done downstream previously and has generally worked. Getting it to work with DLRN is more difficult and sub-optimal due to having to track multiple upstream branches. I'm open to suggestions for how to deal with this challenge and am certainly not stuck on the this being the solution. Thanks Mike [1] http://review.rdoproject.org/r/2042