Removed unnecessary forced compilation of animated template specializations

These don't appear to be necessary anymore. Also reduces .exe output size from to 25.84 MB to 25.78 MB for me, oddly.

src/animated.cpp

@@ -18,13 +18,8 @@
  */
 
 #include "animated.hpp"
-// Force compilation of the following template instantiations
 
-#include "units/frame.hpp"
-
-template class animated< image::locator >;
-template class animated< std::string >;
-template class animated< unit_frame >;
+#include <SDL_timer.h>
 
 // Put these here to ensure that there's only
 // one instance of the current_ticks variable