Replace ast_mod_start -> PBX(moh_start). Beautify sccp extension match helper output.

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@4185 43c1dc8c-776e-4df2-8ef1-6e829299be21
some more checks test with asterisk channel ref; related to #2 #22

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@4186 43c1dc8c-776e-4df2-8ef1-6e829299be21