Update some modes to new API provided by issue #31 of main repo

tetris/modes/marathon_c99.lua

@@ -240,7 +240,10 @@ function MarathonC99Game:onLineClear(cleared_row_count)
         if self.level == 16 then
             self.clear = true
             self.grid:clear()
-            if self.used_randomizer.possible_pieces == 7 then
+            if table.equalvalues(
+                self.used_randomizer.possible_pieces,
+                {"I", "J", "L", "O", "S", "T", "Z"}
+            ) then
                 self.used_randomizer = PowerOnSequence()
                 self.next_queue[1].shape = self.used_randomizer:nextPiece()
             end

tetris/rulesets/pairs.lua

@@ -90,8 +90,6 @@ PAIRS.colourscheme = {
     [18] = "R"
 }
 
-PAIRS.pieces = 18
-
 PAIRS.block_offsets = {
     [1]={
         { {x=-2, y=0}, {x=-1, y=0}, {x=0, y=0}, {x=1, y=0}, {x=2, y=0} },

tetris/rulesets/randompieces.lua

@@ -33,8 +33,6 @@ function RandomPieces:generateBlockOffsets()
     return { { offsets, offsets, offsets, offsets } }
 end
 
-RandomPieces.pieces = 1
-
 RandomPieces.spawn_positions = {
     { x=4, y=5 }
 }