Feature/fix warnings

We should be able to compile using -Wall -Wextra -Werror.

Currently the easy fixes are done, but in the Unstructured load balancer many variables are declared (and set), but not used. I assume, this is the case due to the in progress state of the method.

Other open problems are:

• unused parameters for some implementations of setAdditionalData. If these declaration have to be there we may silence them with proper annotations (for GCC: __attribute__((unused))(ref), which should be put into a compiler dependant preprocessor switch to also set this for clang etc. as well as for readability. Maybe known_unused is a good keyword)
• ignored const on function return (ALL_LB.hpp:163: const int getNVertices() { return vertices.size(); })

This branch should only be merged to refactor after !9 (merged) has been merged!.

include/ALL_Defines.h

@@ -30,7 +30,20 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #ifndef ALL_DEFINES_HEADER_INCLUDED
 #define ALL_DEFINES_HEADER_INCLUDED
 
-// TODO change this depending on the compiler!
+#if defined (__clang__)
 #define known_unused __attribute__((unused))
 
+#elif defined(__GNUC__) || defined(__GNUG__)
+#define known_unused __attribute__((unused))
+
+#elif defined(_MSC_VER)
+#warning "The Microsoft compilers are not supported."
+#define known_unused
+
+#else
+#warning "Unknown compilers are not supported."
+#define known_unused
+
+#endif
+
 #endif//ALL_DEFINES_HEADER_INCLUDED