Refactor

# Features
* Add ability to set initial username
* Add EventData and CustomData to events API
* Allow for unskippable surveys
* Add support for Parse push notifications
* Refactor repo into more Gradle friendly structure
* Added legacy IntelliJ IDEA project files for projects that aren't using Gradle
* Simplify the number of example and test apps that exist in the repo
* 

# Bug Fixes
* Fixed the JsonDiffer to work with zero value numbers
* Fixed Eclipse project files