With the Visual Editor, BROWSE is of dubious value. Even before that,
it was of dubious value. It's the only user of the CASE word, which
is also of dubious value: too complicated for its own good.
The CMD pattern used in VE is much better.
Previously, it would keep the old buffer displayed why typing over
it. I had kept it thus because I didn't want to erase the buffer
right away because the behavior is that when we type nothing, we
keep the buffer as-is and repeat the action.
Now, the behavior of I and F is much better. It keeps the buffer
displayed until the first non-return keystroke and then erases it.
Also, fixed PSP leak in _type and fixed PSP overuse in successful
_F (they balanced out).
Also, made LIST properly handle full 64-chars lines not ending with
a null or CR. Previously, such a line would be accompanied by its
following line, duplicating that line's output.
