* mostly restored the tiled importer unit tests
* code cleanup
* code cleanup
* almost got tiled maps serialization independent of the content pipeline
* refactored the tiled map content importer so that tiled maps can be loaded at runtime
* code cleanup
* removed nuspec files
* experimenting with an XML based GUI markup parser
* a few more markup parser features
* finally got a working open file dialog
* experimenting with markup bindings
* attached properties
* working on the gui stuff again
* working on a better textbox
* multiline textboxing
* new text box is really coming along
* removed the content explorer experiment
* restored the old gui demo back to the way it was before (for now)
Added comments into the importers and processors to show off what the new code does. Removed unneeded code involving locating external files as `Content` handles this for us automatically.
