Jit: Briefly delay start of Jit'ng in attempt to avoid compiling init code

Jit: Briefly delay start of Jit'ng in attempt to avoid compiling init code

Via subjective manual side-by-side testing of jit vs. no-jit, the mterp
version looked like it tended to reach first screen on application launch
very slightly before the Jit version.  This change adds an old and
commonly-used Jit trick to delay jit startup in an attempt to avoid wasting
effort compiling initialization code.

Also, deletes some code no longer in use.