Use the Environment from within the engine

at this point the concept only exists in the engine, the
api and client changes will come in later patches.

blueprint environments
Change-Id: I3e208bb72a04bf275bead2aec89006cf680b501b
Remove unused parameter.user_parameters()

blueprint environments
Change-Id: I21246a62f82064120d6ebd4c5e1c607f43df55bc
Make template_format.parse usable by environments

(environments don't want template sections)

blueprint environments
Change-Id: I68ac0b8fb0889d245ace4d0ea8d298460c4c1b1a
Merge "Use the Environment from within the engine"
Merge "Remove unused parameter.user_parameters()"
Merge "Make template_format.parse usable by environments"