Updated Envelope to properly test against FALSE

Updated the envelope class to check against FALSE, rather than 0 on
returns.
Added CoordinateTransformation class

Added the CoordinateTransformation to wrap the
OGRCoordinateTransformation object. This also required the option to be
able to set "GDAL_DATA" so the class Config under the OSGeo namespace
was added as well.
Added FromEPSG option to SpatialReference

Added the option to create a SpatialReference class from the EPSG code.
This will throw an error on failure.
Fixed up XML comment errors

As some classes do not reference the classes in the header files, for
example the LayerCollection not actually having a link to the DataSource
class (just holds OGRDataSource).
Fixed MultiPoint to hold a Point, not Geometry
Updated Driver

Added SetDriver to Driver::Open as the documentation says to