Metacat

Code added to handle errors resulting from following urls:
http://metacat.nceas.ucsb.edu/knb/metacat?action2 - no action specified
http://metacat.nceas.ucsb.edu/knb/metacat?action=insert - no docid specified
http://metacat.nceas.ucsb.edu/knb/metacat?action=login - no username specified
http://metacat.nceas.ucsb.edu/knb/metacat?action=login&username=uid=sgarg - no password specified
http://metacat.nceas.ucsb.edu/knb/metacat?action=login&username=uid=sgarg&password=random - no qformat specified
http://metacat.nceas.ucsb.edu/knb/metacat?action=logout - no qformat specified
http://metacat.nceas.ucsb.edu/knb/metacat?action=delete with login