Updates and fixes to Mutex (#933)

Updating Mutex to have specific types: TimedMutex, RecursiveMutex, TimedRecursiveMutex. Fixes to the win32 implementation.

test/unit/stdlib/collections/copy_map.c3

@@ -6,7 +6,7 @@ fn void! copy_map() @test
 {
 	TrackingAllocator alloc;
 	alloc.init(mem::heap());
-	io::printfn("Heap mem: %d", alloc.allocated());
+	assert(alloc.allocated() == 0);
     mem::@scoped(&alloc)
 	{
 		HashMap(<String, int>) x;