Summary: Change the following classes into interfaces, with a separate
Impl file: CatalystInstance, ReactInstanceManager,
CatalystQueueConfiguration, MessageQueueThread. This is done to help
isolate the interface between React Native and applications which use it.
This will also help some intrusive development work on a branch
such as porting parts of the bridge to common C++ code, without affecting
app reliability while this work is ongoing.
public
Reviewed By: astreet
Differential Revision: D2651277
fb-gh-sync-id: f04dc04a6e68df7acbc2bbf8b2529287d7b5b2ae
