Bug-fix patch for #404

Surround web call with a try...catch. The exception is silently ignored but needs to be logged.

ref #394
Merge pull request #539 from cwhelchel/fix/i404

Bug-fix patch for #404
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.
Improved: asynchronous load for GenericInventory

Changes:
* Added AsyncGenericInventory.cs
* Fixed display Deserialization errors
* Fixed  not being able to use TradeUserAsset on Inventory.GetItem(...)