Make crow clock out always rise on the given division. (#1497)

* Make crow clock out always rise on the given division.

Previously, it would either rise on the division and fall halfway
between the divisions or vice versa, and which one would be based on
the vagueries of timing.

* Actually only do it if crow out is enabled

lua/core/clock.lua

@@ -270,13 +270,13 @@ function clock.add_params()
 
   -- executes crow sync
   clock.run(function()
-    local v = 0
     while true do
-      clock.sync(1/(2*params:get("clock_crow_out_div")))
+      clock.sync(1/params:get("clock_crow_out_div"))
       local crow_out = params:get("clock_crow_out")-1
       if crow_out > 0 then
-        crow.output[crow_out].volts=v
-        v = (v==0) and 10 or 0
+        crow.output[crow_out].volts = 10
+        clock.sleep(60/(2*clock.get_tempo()*params:get("clock_crow_out_div")))
+        crow.output[crow_out].volts = 0
       end
     end
   end)