Mostly adding tests and documentation.

Mostly adding tests and documentation.

Rename sub print_preprocessor_statements() to
analyze_preprocessor_statements().  Modify interface to map_type() and
re-work tests as needed.  Wrote documentation in Utilities.pm for
process_single_typemap(), map_type(), standard_XS_defs(),
assign_func_args(), analyze_preprocessor_statements().  Write tests
in t/109-standard_XS_defs.t, t/110-assign_func_args.t.