Completely replace animate system for entities

This removes the magic numbers used for `animate`, and makes the
animation system far more flexible, instead giving entities the option
to control what they need, instead of having a bunch of duplicated
hardly-readable code.

desktop_version/src/Ent.cpp

@@ -22,7 +22,6 @@ void entclass::clear(void)
     colour = 0;
     para = 0;
     behave = 0;
-    animate = 0;
 
     xp = 0;
     yp = 0;
@@ -69,6 +68,10 @@ void entclass::clear(void)
     SDL_zero(realcol);
     lerpoldxp = 0;
     lerpoldyp = 0;
+
+    animation_frames = 4;
+    animation_type = EntityAnimationType_OSCILLATE;
+    animation_speed = 8;
 }
 
 bool entclass::outside(void)

desktop_version/src/Ent.h

@@ -52,6 +52,16 @@ enum EntityRenderTypes
     EntityRenderType_SPRITE_6x
 };
 
+enum EntityAnimationTypes
+{
+    EntityAnimationType_STILL,
+    EntityAnimationType_OSCILLATE,
+    EntityAnimationType_LOOP,
+    EntityAnimationType_ONESHOT,
+    EntityAnimationType_CONVEYOR_LEFT,
+    EntityAnimationType_CONVEYOR_RIGHT
+};
+
 class entclass
 {
 public:
@@ -77,7 +87,7 @@ class entclass
     EntityRenderTypes render_type;
     int tile, rule;
     int state, statedelay;
-    int behave, animate;
+    int behave;
     float para;
     int life, colour;
 
@@ -98,6 +108,9 @@ class entclass
     int onground, onroof;
     //Animation
     int framedelay, drawframe, walkingframe, dir, actionframe;
+    int animation_frames;
+    EntityAnimationTypes animation_type;
+    int animation_speed;
     int collisionframedelay, collisiondrawframe, collisionwalkingframe;
     int visualonground, visualonroof;
     int yp;int xp;