relax SVN archive

Updated the runcode() docstring for the epydoc format.

Converted the default quit arg of run_script() to a bool.

Updated the run_script() docstring for the epydoc format.

Updated the prompt() docstring for the epydoc format.

Updated the interact_script() docstring for the epydoc format.

Converted the interact_prompt() args to keyword args and epydoc'd the docstring.

prompt.interpreter.interact_script() has been modified to allow RelaxErrors to be raised.

Previously running a script would catch the error, send a nice message to STDERR, and quit. Now
the function can raise the error if asked. This is required for the system tests (because of the
unittest framework). Alternatively the status of the script could have been used by the test, but
this is easier for the test writer and makes the code more flexible.

The status of script execution is now returned by the run() interpreter method.

Nothing currently uses this.

Tidied up the interact_script() function (with comments). The function also returns its status.

The status is obviously only returned if relax doesn't not quit.

All the model-free optimisation tests now run the opt_setup_S2_0_970_te_2048_Rex_0_149.py script.