allow buttons to interrupt events

Dependencies

• [2] WJBZZQE4 fold together two largely similar cases
• [3] PW2VGQWN indent
• [4] LNUHQOGH start passing in Editor_state explicitly
• [5] XX7G2FFJ intermingle freehand line drawings with text
• [6] 2L5MEZV3 experiment: new edit namespace
• [7] LF7BWEG4 group all editor globals

Change contents

• edit in edit.lua at line 165
  [2.935]

  [2.935]
  + return true -- don't handle any other events with this mouse button press
• replacement in edit.lua at line 211
  [4.4647]→[4.6966:7016](∅→∅),[4.100368]→[4.6966:7016](∅→∅),[4.6966]→[4.6966:7016](∅→∅)
  − propagate_to_button_handlers(x,y, mouse_button)
  [4.4647]

  [4.7016]
  + if propagate_to_button_handlers(x,y, mouse_button) then

  + -- press on a button and it returned 'true' to short-circuit

  + return

  + end
• replacement in button.lua at line 18
  [3.66]→[3.66:88](∅→∅)
  − ev.onpress1()
  [3.66]

  [3.88]
  + return ev.onpress1()