relax SVN archive

Rewrote the intensity_generic() function.

This is now much simpler (5 lines of code).

Fixes for the test_read_peak_list_generic() system test.

Complete redesign of the generic_fns.spectrum module.

This significantly simplifies the code base (much less jumping between functions) and prepares for
the generically formatted file support.

Added the new error class RelaxArgNotNoneError for when an argument should be None.

Commented out the header.

Deleted the test_read_peak_list_generic2() system test.

This was just duplicating test_read_peak_list_generic().

Redesigned the test_read_peak_list_generic() system test.

Renamed generic_intensity2.txt to generic_intensity.txt.

Removed some unneeded files.

The relaxation delays will be placed into the script itself, and the generic_intensity2.txt file
will replace generic_intensity.txt.

Fixes for the system tests to use the new 'align_id' args.