Support metadata in piston pushing (so that microcontrollers and such can be pushed), support pushing chests (not locked ones though), and add two missing rules for pistons (z- top and bottom, but not z- itself). This still avoids the piston pushing power source issue.

mesecons_pistons/init.lua

@@ -8,7 +8,9 @@ piston_rules =
  {x=-1, y=1,  z=0},
  {x=-1, y=-1, z=0},
  {x=0,  y=1,  z=1},
- {x=0,  y=-1, z=1}}
+ {x=0,  y=-1, z=1},
+ {x=0,  y=1,  z=-1},
+ {x=0,  y=-1, z=-1}}
 
 local piston_get_rules = function (node)
 	local rules = piston_rules