use available variables

Dependencies

• [2] P5QNVXSN drop final mention of state global beyond main.lua
• [3] RT6EV6OP delegate update events to drawings
• [4] PJEQCTBL add state arg to Drawing.update
• [5] UHB4GARJ left/right margin -> left/right coordinates
• [6] LF7BWEG4 group all editor globals
• [7] LAW2O3NW extract variable Margin_left
• [8] DRFE3B3Z mouse buttons are integers, not strings
• [9] JFFUF5AL override mouse state lookups in tests
• [10] KTZQ57HV replace globals with args in a few functions
• [11] EHSUSZMK more idiomatic variable names
• [*] BLWAYPKV extract a module

Change contents

• replacement in drawing.lua at line 248
  [3.433]→[2.1306:1464](∅→∅)
  − table.insert(drawing.pending.points, {x=Drawing.coord(App.mouse_x()-State.left, State.width), y=Drawing.coord(App.mouse_y()-drawing.y, State.width)})
  [3.433]

  [3.565]
  + table.insert(drawing.pending.points, {x=Drawing.coord(pmx-State.left, State.width), y=Drawing.coord(pmy-drawing.y, State.width)})