Figure out interactions with mouseleave

[weiseng18]

The main issue with mouseleave is whether to treat it like a mouseup and terminate any mousemove action, or to pause it and allow it to resume on mouseenter

• mouseleave with select tool
  • stop select at last point before last leave?
  • allow select from previous to continue on mouseenter?
• mouseleave on #color_body
  • stop select at last point before last leave?
  • allow select from previous to continue on mouseenter?

[weiseng18]

mouseleave interactions

move tool

refer to #14

select tool

works the same as move tool, refer to #14