Make sure default value for STRINGPTR is "" wenn parsing defaults (non-issue)

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@4451 43c1dc8c-776e-4df2-8ef1-6e829299be21
Add Promote/Demote to conference (under CS_EXPERIMENTAL). This makes it possible to promote someone else to moderator and then demote yourself, this way multiple moderators can manage a large conference or you can leave a conference without tearing it down.

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@4452 43c1dc8c-776e-4df2-8ef1-6e829299be21