Basic API methods
Sample method for getting Persons, JSON parsing

Added example application.
Structure fixes
More structure fixes.
Switched to retrofix. Updated Android demo
Added NetworkError, Buildings, Rooms.
Additional documentation
Minor comment fixes
Generic types for deserialization
Removed debug message
AbstractAPIClient
Merge pull request #1 from ZolnaiDani/master

Basic structure, Persons, Buildings, Rooms, Android demo