relax SVN archive

Created the pipe.list() user function for printing a list of all the data pipes.

Created the pipe.switch() user function for switching between data pipes.

Two unit tests were created for the new code - test_switch() and test_switch_fail().

Created the new pipe.current() user function.

The pipe.create() user function now works!

The prompt.pipe module now import the 'generic_fns.pipes' module and executes the create() function.
The system/functional test for this user function now passes and has been updated with runs renamed
to pipes.

Removed the functions not used by relax from the 'generic_fns.pipes' module.

The functions 'eliminate_unused_pipes()' and 'list_of_pipes()' have been deleted as they are not
used anywhere within relax. The unit test for the 'eliminate_unused_pipes()' has also been deleted.

Fixed the setting of the current data pipe so that the 'test_deletion()' unit test passes.

The current data pipe was not being set to None by the 'generic_fns.pipes.delete()' if the deleted
pipe is the current pipe.

Fixed the setting of the current data pipe so that the 'test_creation()' unit test passes.

The current data pipe was not being set to the new data pipe created by the function
'generic_fns.pipes.create()'.

Fixed the 'test_deletion_fail()' unit test.

The error throw was RelaxNoRunError and not RelaxError.

Rewrote the 'generic_fns.pipes.delete()' function.

Added a tearDown() method to the 'test_suite/unit_tests/generic_fns/test_pipes.py' file.

The relax data storage object is reset as the data added to it from different tests was clashing.
The method allows the 'test_creation_fail' unit test to pass.