various improvements from MapBox 0.5.0 release
o Refactored contraints so that tilesource constraints are always intersected with user supplied constraints
o Merge fix
o Removed unnecessary RMRequireAsset calls in [RMMapView setShowsUserLocation:]
o Licence and copyright updates
o Changed [RMMapView resourceImageNamed:] so that we don't need an image bundle in this fork
o Sample code updates
o Project update
o Prevent double tile downloads
RMMapTiledLayerVie::drawLayer will call URLForTile when trying to draw/cache tiles.
Merge pull request #130 from jacksonh/release

RMMapTiledLayerView::drawLayer calls URLForTile
o Some code improvements (NS_ENUM, instancetype)
o Better synchronization for annotations in the quad tree
Merge branch 'release' into develop
o Implementation of the UTM coordinate grid in RMCoordinateGridSource
Merge branch 'develop' into release
WMS Tile Source
o Refactoring for a unified code style
o Added the new WMS source to the MapTestbedFlipMaps sample project
o Sample code updates