Fix 65 Use ⎕DQ rather than ⎕TGET

[mkromberg]

For review only - do not merge.

In order to capture HTMLRenderer events, switch to using ⎕DQ rather than ⎕TGET to displatch incoming events from the web socket.

The "code" namespace already contains a Timer object called _EWC.TIMER, which was used to enable interactive DQ. In the new strategy, ∆DQ is always doing a ⎕DQ of that object, and instead of using TGET/TPUT to transfer events to ∆DQ, EWC.Handler ⎕NQ's a 1001 event to the TIMER, which calls the function dqTimer.

• If we are in a ∆DQ, the event is re-enqueued as a 1002, which causes the ⎕DQ in ∆DQ to terminate so the event can be handled in that function.
• If we are NOT in ∆DQ ("interactive mode"), dqTimer handles the event itself. This should possibly still be controlled by the NOIDQ switch.