Add a submodule for CMake C++11 detection scripts.

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http://quickgit.kde.org/?p=scratch%2Fdakon%2Fcmake-cxx11.git
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Port over differing-lua-version support.
Fix configured header
Fix Lua include directory
Optionally enable C++11 support
Switch branches of cxx detection.
Shuffle the c++11 detection stuff.
Put a define guard to prevent re-definition.
Remove redundant check
Make building header tests possible with GUI
Add configuration option LUABIND_NOT_THREADSAFE to the build.
Comment out something I'm unsure of.
start fixing tests with LUABIND_NO_EXCEPTIONS turned on.
Handle warnings and other compiler flags