Fix for OS X Mavericks (10.9) compilation and build errors

Starting from Mac OSX 10.9 (Mavericks) the default C++ standard library changed to libc++ (the LLVM library). This switch has caused (and still causes) a lot of issues because the new library is more stringent on non-standard C++. For example Orocos KDL uses non-standard C++ in the TreeNode class thus it is not possible to build it with libc++ (see related Github issue).

You can (and must) build KDL by explicitly specify the old GNU C++ library. You can do this by toggling the advanced CCMake configuration (t key) and by adding in both CMAKE_CXX_FLAGS and CMAKE_EXE_LINKER_FLAGS the following string: -stdlib=libstdc++.

One issue still remains. It is not clear if two applications can link (shared linking, not static linking) at the same time the GNU and LLVM C++ library. For sure Homebrew does not allow it. You can check which shared libraries an application (or another shared library) links by issuing the following commands:

otool -L library_name

E.g.

$ otool -L libYARP_OS.dylib 
local/lib/libYARP_OS.dylib:
    libYARP_OS.1.dylib (compatibility version 1.0.0, current version 2.3.60)
    /usr/local/lib/libACE.dylib (compatibility version 0.0.0, current version 0.0.0)
    /usr/lib/libstdc++.6.dylib (compatibility version 7.0.0, current version 60.0.0)
    /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1197.1.1)