Move all enum types definitions to types.h

Cleanup headers while there.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

src/movepick.cpp

@@ -24,7 +24,7 @@
 #include "movegen.h"
 #include "movepick.h"
 #include "search.h"
-#include "value.h"
+#include "types.h"
 
 namespace {