relax SVN archive

More info is now being placed into the software containers of the experimental info container.

Many fixes to the Element and ContainerList to_xml() methods.

The objects within these are now properly converted to XML with the to_xml() method beign called
if it exists.

Expanded the experimental information data container to include all the software info.

The bmrb.software_select() user function is now more functional.

Modified the system test to force save the program state.

Created the ContainerList base class object.

This is just a generic list type with XML methods, used to hold basic elements.

Created the user function bmrb.software_select().

This currently doesn't do anything.

Created a data container for storing experimental details.

This will be used extensively for the BMRB file generation.

The program state is now being saved in the BMRB system test.

Comment fix.