Bug 1617: We don't need a configure test for __cxa_demangle(). Every GNU C++ compiler supports it, so we can simply test for the __GNUG__ preprocessor variable.

bug 1362: properly check for getprotobyname_r, which is not available on Mac OS/X and has a different calling convention on Solaris

around problem with incompatible declaration of basename() in string.h which
uses strict ISO prototyping when using g++ >= 4.4

Note: changes in RTCP still need to be committed, awaiting aproval of John Romein

maintainable. 

branch LOFAR-Bug1310-task-branch with the trunk.

rev. 12447-13413 with the trunk.