Commit of the directrtp project

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@4790 43c1dc8c-776e-4df2-8ef1-6e829299be21
DirectRTP compile fixes for asterisk-1.6 / asterisk-1.8 / asterisk-1.10

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@4791 43c1dc8c-776e-4df2-8ef1-6e829299be21