flip return value of button handlers

Dependencies

• [2] PP2IIHL6 stop putting button state in a global
• [3] WJBZZQE4 fold together two largely similar cases
• [4] 2L5MEZV3 experiment: new edit namespace
• [5] U76D4P36 fix a typo
• [6] LNUHQOGH start passing in Editor_state explicitly
• [7] OAHNWDYG .
• [8] ZNLTRNNK highlight another global
• [9] XX7G2FFJ intermingle freehand line drawings with text
• [10] ILOA5BYF separate data structure for each line's cache data
• [11] 6D5MOJS4 allow buttons to interrupt events
• [12] BJ46QVIP improve explanation for buttons
• [13] TGHAJBES use line cache for drawings as well
• [14] PW2VGQWN indent

Change contents

• edit in edit.lua at line 166
  [3.935]→[3.15:113](∅→∅)
  − return true -- don't handle any other events with this mouse button press
• replacement in edit.lua at line 211
  [3.4647]→[2.114:179](∅→∅)
  − if propagate_to_button_handlers(State, x,y, mouse_button) then
  [3.4647]

  [3.172]
  + if mouse_press_consumed_by_any_button_handler(State, x,y, mouse_button) then
• replacement in button.lua at line 3
  [3.117]→[3.117:203](∅→∅)
  − -- If the handler returns true, it'll prevent any further processing of the

  − -- event.
  [3.117]

  [3.2080]
  + -- If any applicable button handler returns true, it'll propagate the click to other handlers.
• replacement in button.lua at line 17
  [3.2443]→[2.344:409](∅→∅)
  − function propagate_to_button_handlers(State, x, y, mouse_button)
  [3.2443]

  [2.409]
  + function mouse_press_consumed_by_any_button_handler(State, x, y, mouse_button)
• replacement in button.lua at line 24
  [3.66]→[3.258:287](∅→∅)
  − return ev.onpress1()
  [3.66]

  [3.88]
  + return not ev.onpress1()