Improved on some glitchy 3-way corners involving beach waves

Corners where water, sand and anything that sand transitions over (such as roads) exhibited the problem. This fix isn't perfect as the convex and concave shore waves don't completely match, but it's a clear improvement.

data/core/terrain-graphics/new-macros.cfg

@@ -1004,6 +1004,8 @@
         [/image]
     [/terrain_graphics]
 
+    # These 4 rules draw very special convex-concave combination rules in 3-way
+    # sand-water-other corners
     [terrain_graphics]
         map="
 ,  2
@@ -1014,29 +1016,62 @@
         [tile]
             pos=1
             type={TERRAINLIST}
+            no_draw=yes
         [/tile]
         [tile]
             pos=2
             type={ADJACENT}
-            set_no_flag=waves_convex-@R0-@R5
         [/tile]
         [tile]
             pos=3
             type=!,{TERRAINLIST},{ADJACENT}
+            no_draw=yes
         [/tile]
 
         rotations=tr,r,br,bl,l,tl
 
         [image]
-            name={IMAGESTEM}-convex-A[01~13].png~MASK(terrain/masks/7hex-@R0-@R5.png):200
+            name={IMAGESTEM}-convex-A[01~13].png~MASK(terrain/masks/7hex-@R0.png):200
             random_start=no
             layer={LAYER}
             center=90,144
             base=90,144
             is_water=yes
         [/image]
     [/terrain_graphics]
+    [terrain_graphics]
+        map="
+,  2
+*,   3
+,  1
+*,   *
+,  *"
+        [tile]
+            pos=1
+            type={ADJACENT}
+            no_draw=yes
+        [/tile]
+        [tile]
+            pos=2
+            type=!,{TERRAINLIST},{ADJACENT}
+            no_draw=yes
+        [/tile]
+        [tile]
+            pos=3
+            type={TERRAINLIST}
+        [/tile]
 
+        rotations=tr,r,br,bl,l,tl
+
+        [image]
+            name={IMAGESTEM}-concave-A[01~13].png~MASK(terrain/masks/7hex-@R0-@R1.png):200
+            random_start=no
+            layer={LAYER}
+            center=90,144
+            base=90,144
+            is_water=yes
+        [/image]
+    [/terrain_graphics]
     [terrain_graphics]
         map="
 ,  2
@@ -1047,21 +1082,55 @@
         [tile]
             pos=1
             type={TERRAINLIST}
+            no_draw=yes
         [/tile]
         [tile]
             pos=2
             type=!,{TERRAINLIST},{ADJACENT}
+            no_draw=yes
         [/tile]
         [tile]
             pos=3
             type={ADJACENT}
-            set_no_flag=waves_convex-@R0-@R1
         [/tile]
 
         rotations=tr,r,br,bl,l,tl
 
         [image]
-            name={IMAGESTEM}-convex-A[01~13].png~MASK(terrain/masks/7hex-@R0-@R1.png):200
+            name={IMAGESTEM}-convex-A[01~13].png~MASK(terrain/masks/7hex-@R0.png):200
+            random_start=no
+            layer={LAYER}
+            center=90,144
+            base=90,144
+            is_water=yes
+        [/image]
+    [/terrain_graphics]
+    [terrain_graphics]
+        map="
+,  2
+*,   3
+,  1
+*,   *
+,  *"
+        [tile]
+            pos=1
+            type={ADJACENT}
+            no_draw=yes
+        [/tile]
+        [tile]
+            pos=2
+            type={TERRAINLIST}
+        [/tile]
+        [tile]
+            pos=3
+            type=!,{TERRAINLIST},{ADJACENT}
+            no_draw=yes
+        [/tile]
+
+        rotations=tr,r,br,bl,l,tl
+
+        [image]
+            name={IMAGESTEM}-concave-A[01~13].png~MASK(terrain/masks/7hex-@R0-@R5.png):200
             random_start=no
             layer={LAYER}
             center=90,144