relax SVN archive

Converted the map_space() base class method into the __init__() method.

Fixed a function vs. arg name clash.

Improvements to the dx.execute() user function.

Completed the run() function docstring.

Changed how the OpenDX map type string is matched.

Added a missing import.

Fixes for the interface of the map() user function.

More fixes for the system tests of the OpenDX mapping of model-free spaces.

Fixes for the system tests of the OpenDX mapping of model-free spaces.

Converted the map() user function interface to the new relax design.