relax SVN archive

Edit of the module docstring.

Clean up of the prompt.interpreter module.

This includes the merging of the _auto_generate() method into _setup() and the clean up of the imports.

Updated the module docstring.

Fix for two of the arg_check.is_*() fns - the individual elements were incorrectly checked.

Created RelaxValListValError and RelaxNoneValListValError for the arg_check.is_val_or_list() fn.

The prompt UI can now handle the user function arg type of 'val_or_list'.

Eliminated the try logic in the arg_check is_*() fns as the raise_error flag can now be used instead.

The change at r16136 in the main 1.3 line allows this simplification.

Created the arg_check.is_val_or_list() function for the value.set user function.

The value argument of this user function is now classified as a 'val_or_list' object, hence this
is_val_or_list() replaces the use of is_str_or_num_or_str_num_list().

Clean up of the prompt package __init__ module.

Converted the vmd user functions to the auto-generation design.