add parameter-based lfo scripting library (monome#1585)

* initial upload + unload lfo's after use

* default = 'param action' and track fn mapping

* add function type lookup table

* add ldoc notes

* bars -> clocked

* no spaces in param IDs

* remove 'frm', not used

* rename library to 'param_lfo'

* rename to 'param-lfo'

* p_lfo -> plfo

just cosmetic, but looks way better

lua/core/script.lua

@@ -27,6 +27,10 @@ Script.clear = function()
     package.loaded['asl'] = nil
   end
 
+  if package.loaded['param-lfo'] then
+    package.loaded['param-lfo'] = nil
+  end
+
   -- script local state
   local state = { }