additionally, remove unused caching features and update mongo indexing.

remove recursive queries in comment thread views

add simple filtering on inbound content based on a collection of forbidden content bodies

force moped v1.2.1

restore deep search with reindex fix

quick fix to skip the second document reimport when it is *not* necessary (first time index creation).

* properly handle when the index/alias don't yet exist
* don't lose content updates made while reindex/rebuild are in progress
* when possible, use tire api's reindex call for much more efficient index changes
* expose rake tasks to explicitly rebuild or reindex individual types

avoids Moped::Errors::OperationFailure "need to login" in edx loadtest environment

Conflicts:
	Rakefile

restore notifications api post-merge-rollback

Revert "Merge pull request #41 from edx/feature/kevin/deep_search"

un-merge deep search, as we've rolled it back on prod.

This reverts commit 5f90d8fd, reversing
changes made to 55cc9867.