Templates: back button goes to preferences not conversation list

Change-Id: Ib12e521b5049b0139ad638edb3a1583c3410cac5
Don't recycle messages by default.

* Don't delete old messages by default.
* If any of the conversation threads have more messages than
  the storage limit settings, an activity is shown that will
  tell the user how to turn on the storage limits.
* This changes the behavior introduced in commit
  f766f33b774cfb6dd4100a6522ffa23c0a0dae35

Change-Id: I7e20ec73fbe42e19397cda2663de7434557f0e51
Fix IllegalStateException.

The pager must be notified of changes in its underlying data.

JIRA:CYAN-1703
Change-Id: I473e03e546665f5a159e2af43b389c0d83dc9928
MediaModelFactory.findPart moved to SmilHelper for use in both places.
findPart updated to include looking in ContentId even if the "src" does not have the cid: prefix. Noticed from a Stock GS4.
SmilHelper now has a fixup(...) method which removes duplciate parts.

Change-Id: I1e1b6b0792888797123fadd795dd33b141ce8ea2