Add more unit tests for ThreadGroupManager

this patch adds unit tests for the rest of ThreadGroupManager methods.
Related-Bug: #1288627
Change-Id: I38a0864c649d1693ef4fb5b49d5aeb37632263ca
Don't re-bind parameters during stack update

While we're in the process of updating a stack, we set the stack's parameters
to the new, updated values. However, we don't want to change existing
resources' idea of their own values until we have explicitly done an update of
them to bring them into line with the new template/parameters. So when parsing
a template snippet, store the parameters object to which it will refer.
References will resolve to the new parameters only when the template has been
re-resolved.

Closes-bug: #1291411

Change-Id: Iebbb518c5d15cfba858db001648f3412a7d8b1c0
Merge "Add more unit tests for ThreadGroupManager"
Merge "Don't re-bind parameters during stack update"