Update 9/23/14 - Project Browsing, Data Manager, SampleRate/RecordingLength

Ref issue #7

- Project browsing and ID retrieval in Motion implemented
- Sample interval and recording length in Motion implemented
- New DataManager (to replace DataFieldManager) created, implementation finished besides row-major-to-column-major (not being implemented until needed in case DM format changes during Motion implementation)
- Smart RProjectField object that now has a recognized_name field, performing the field matching autonomously on creation of the object
- Field matching implemented in Motion

@jaypoulz 
Remove the != nil here.