Replace conf-enteringno by conf-placeintoconf (fixes #87)

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@4439 43c1dc8c-776e-4df2-8ef1-6e829299be21
Add debug logging to sccp_conference, to find mute issue. Elaborate on error description when open_receive_channel returns status error

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@4440 43c1dc8c-776e-4df2-8ef1-6e829299be21