relax SVN archive

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.

Converted the map() and run() functions to the new relax design.

Renamed the opendx.opendx module to opendx.main.