[CMake][Bugfix] Fix search for test directories.

The patch from ...fce82c7d5ee5 broke the script.
This is the intended behavior.
[CMake] Rename FindCXX*.cmake and FindSharedPtr.cmake.

They do not find a package but check for a feature.
This avoids false warnings about not found packages.
Merged FindCXX11Conditional.cmake and FindCXX11Features.cmake.
[CMake] Code beautification.

Avoid upper case commands.
Merge branch 'master' of http://git.dune-project.org/repositories/dune-common

Conflicts:
	cmake/modules/CheckCXX11Features.cmake