Swift fix and minor fixes

RNRK.initialize now takes a config object passed into the function. showOverlay is the first option.

@samridhgupta:
Fix for Swift 3 no longer being supported in latest xcode from
Refactor the recording naming code, recordings names by datestamp now
Recordings sorted by date in the callbacks

initial

initialize
startRecording
stopRecording
getRecordings
previewRecording
copyRecording
deleteRecording

tested and working.. hope some others verify though