Fix: also deal with the bad config example 'button = line, empty', that was accidentally distributed.

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5650 43c1dc8c-776e-4df2-8ef1-6e829299be21
Doc: Update/Fix Doxygen

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5652 43c1dc8c-776e-4df2-8ef1-6e829299be21