Refactor of custom/code_types.inc.php to use metadata describing the
various tables.
additional explaination in lookup_code_descriptions
Snomed support improvements and bug fixes (take 3):

 -Supports import of snomed Spanish International code set
 -Searching function will support any snomed language international code set
 -Supports importing of snomed US extension set that procedes the main snomed English International set
 -Supports filename of the 03-01-2012 snomed US extension code set
 -Added a snomed procedure code type

 This has been fully tested, however am awaiting completion of
 project discussed in following thread before committing this
 into the official codebase (note there will need to be some
 integration work in custom/code_types.inc.php that is
 dependent on that project):
 http://sourceforge.net/projects/openemr/forums/forum/202506/topic/6686760

 Merged into above forum code for testing 2-5-2013.
Code types module fixes and improvements.

 -fixed minor financial reporting flag bugs
 -implemented mechanism for sequential searching
 -using new sequential implementation mechanism
  throughout entire codebase

 NOTE: The sequential code searching mechanism was
       contributed by yehster.

 Merged into meta-data code type mechanism code on 2-5-2013.
Switch snomed join order (descriptions->concepts)
handle empty string in description search
additional comments for code set refactor