Handle all three event in a similar manner

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5058 43c1dc8c-776e-4df2-8ef1-6e829299be21
Added required/optional comments to events. Fixed pbx_log output

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5059 43c1dc8c-776e-4df2-8ef1-6e829299be21