can get "stale" and cause DrRacket to deadlock (this commit just sets
up some stuff to make one fix possible, but that fix doesn't seem to
be working, so the actual fix is disabled (see comment in commit))
this also gets rid of the module-level imports as annotations in the bar
along the buttom of a drracket window, which eliminates the use of the
'drracket:check-syntax:mouse-over status line and thus:
closes PR 12186
being edited in DrRacket (via places)
Added an API to let tools have access to that
information (and compute more stuff)
Used that to make an online version of Check Syntax
which led to a separately callable Check Syntax API.