Fix: file header

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5673 43c1dc8c-776e-4df2-8ef1-6e829299be21
Fix: ast-13 compilation with conference. Fix: const/non-const compile warning

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5674 43c1dc8c-776e-4df2-8ef1-6e829299be21
Revert sccp_channel.c sccp_device.c from previous commit (accidentally checked in)

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5675 43c1dc8c-776e-4df2-8ef1-6e829299be21