Implemented REST API for GameAnalytics

[loonychewy]

• Added support for UNITY_STANDALONE platforms for GameAnalytics
• Modified the GameAnalytics for Unity plugin directly
• Includes a dependency to plugin Unity.IO.Compression, although this seems to be necessary only for Unity 4.X
• Also added compilation preprocessors GAME_ANALYTICS_IN_EDITOR and GAME_ANALYTICS_AGGREGATED. The former is to allow GameAnalytics tracking in editor (useful for debugging GameAnalytics), and the latter is used for aggregating all trackers under one game in GameAnalytics
• Implements the GameAnalytics REST API according to documentation: http://apidocs.gameanalytics.com/REST.html
• Updated GA_MiniJson to support int data types. Technically, json spec only supports floats, but because of this, large integers (such as unix timestamps) are serialised to float, which doesn't pass the json schema test as a result for submitted event data as a result
• For standalone builds, pass the GameAnalytics instance to GA_Wrapper class, as the REST API implementation needs a MonoBehavior instance to call coroutines

[the1schwartz]

Hi,

Thank you for your contribution. At the moment we have stored the pull request in a separate branch from the master branch in our development repository. We will review your code contribution and will try to re-use as much possible. We are considering ourselves to make a REST API implementation for our Unity SDK to be used for Unity's supported platforms other than the mobile platforms which should be ready in the near future.

Kind regards, Martin SDK Developer @ GameAnalytics