parse _ALERT_INFO/__ALERT_INFO during call request

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@4295 43c1dc8c-776e-4df2-8ef1-6e829299be21
remove ALERT_INFO parsing, remove complexity for dnd and ringermod

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@4296 43c1dc8c-776e-4df2-8ef1-6e829299be21