Revise OpenReceive/StartMediaTransmission

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5452 43c1dc8c-776e-4df2-8ef1-6e829299be21
Update handling of orcStatus

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5453 43c1dc8c-776e-4df2-8ef1-6e829299be21