relax SVN archive

Redesign of the relax state loading for adding support for a XML formatted state file.

Half of the load_state() is now in load_pickle(), and a new function load_xml() added.
The determine_format() function will tell if the file is a pickle or XML file, and then
load_pickle() will run the appropriate loading function.

A few fixes for the test_write_read_pipes() system test.

Shifted the test_write_read_pipes() system test to the 'state' test module.

The program state is now being saved as the results file is for just one data pipe.

Updated the specific_fns module __all__ list for the SRLS module.

Added a very basic, and completely empty module and class for SRLS analysis.

This is to allow the data pipe to be created.

Removed an empty line.

Deleted the __init__() class methods as these were empty, and shifted the docstring to that of the class.

The test_write_read_pipes() system test is now using the VALID_TYPES module variable to get all pipes.

Shifted the valid types private function variable into a module variable.

Wrote a system test for the writing and re-reading of data pipes.