Optimize headers (part 2) (#6272)

* Optimize headers (part 2)

* less debug.h in headers
* less remoteplayer.h for everybody

* Cleanup (part 2)

* camera.h: mesh.h
* mapgen.h: mapnode.h
* serverenvironment.h: mapblock.h
* nodedef.h: shader.h

src/map.h

@@ -33,6 +33,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "util/container.h"
 #include "nodetimer.h"
 #include "map_settings_manager.h"
+#include "debug.h"
 
 class Settings;
 class MapDatabase;