Files support for Hybrid application

1) new api wrappers (see forcetk.mobilesdk.js)
2) support for custom rest end points (see Force.RemoteObject and Fore.RemoteObjectCollection in smartsync.js)
3 tests for new api wrappers (see SFForcetkTestSuite.js)
4) new sample application (see FileExplorer.html) - it takes advantage of Force.RemoteObject and Force.RemoteObjectCollection to get files list and details using new files api wrappers

1) + 3) is really simple stuff
2) has is the most interesting one

Not there: upload support (probably need to be spiked first)