Code type module improvements:

Code type module improvements:

 -Added wrappers to the code set search module functions to ease use.
 -Full support for multiple code type searching.
 -Support of short descriptions.
 -Support for new functionality in Administration->Services.
 -Added test calls in the Testing scripts
 -Consolidated the internal/external code search methods in code_set_search() function
 -Added ability to search code sets by category