Fixed compiler warnings and bug causing case sensativity for OPUS, speex and G722


git-svn-id: http://scm.sipfoundry.org/rep/sipX/main@12258 a612230a-c5fa-0310-af8b-88eea846685b
Comments on codec enum values


git-svn-id: http://scm.sipfoundry.org/rep/sipX/main@12259 a612230a-c5fa-0310-af8b-88eea846685b