Adds User Handler feedback on bot's trade request accept/decline.
Merge pull request #531 from FrozenHaxor/master

Adds User Handler feedback on bot's trade request accept/decline.
Generic Trade

TradeUserAssets-related methods and properties improvement
Small fixes

* Updated forgotten handlers.
* Renamed documentation directory.
* Added jsonResponse.IsLoaded = true to GenericInventory.cs when
inventory loads correctly.