This also appears to fix crashes when running ReactTests with Chrome debugging enabled!
The crash when tests failed was due to JavaScriptCore trying to create a backtrace with the native call stack.
The deleteTestFiles() function is now added to the Realm object, so that it's easy for the RPC module to handle this as well. We can only do this in testing environments in the future.
It embeds RealmJS and GCDWebServers frameworks. This fixes#58, where there were issues with building for devices rather than just the simulator.
Some changes were made so that RealmReact.m didn't need to be weakly linked to libReact.a since that would actually cause any executable that uses this framework from being able to compile with bitcode.