Handlers Interface to Datastore

Changes:

* Changed abc to be an abstract base class that inherits from App Engine's ndb.Model
    * added 4 properties that are shared across all profiles
* Implemented properties specific to Facebook and LinkedIn Profiles in concrete classes
* Interface for @Fuss04 from Handlers to the Datastore
* Refactored out authentication into separate class for when we implement a code generator
* Did some renaming
* Removed all traces of eclipse/pydev (everyone should be using Sublime or something similar)