Modify Makefile to build rpms from local git clones.

The only modification to the spec files is to allow the Version and Release
to be passed in from Makefile.

The Makefile now generates dev snapshot RPMs of heat master. RPMs for actual
releases can be managed by release branches of heat-rpms.

I've made as few changes as possible to the heat-jeos RPMs as I'm about
to nuke the project, to be replaced by heat-cfntools
Make targets for managing yum repository.

Hard-coding this to Fedora 17 is temporary, eventually this build system
should switch to mock.
Package heat-cfntools instead of heat-jeos
Ignore yum-repo
Build the yum repo metadata
Use mock to build rpms for fedora 16,17,18 and epel 6.

In the process, the directory layout of rpm-build is now the default layout.
fix make all
Merge pull request #11 from steveb/master

Refactor to build heat-cfntools, use mock and sync to yum repo