[Bug translator/4935] support on-the-fly probe enable/disable syntax

[Frank Ch. Eigler]

Hi -

> I developed a patch for the parser and the elabolator to support
> this syntax.  Currently, this just translates the next script; [...]
> This is the first step of this feature, since this patch does not
> include optimization code.

It is a fine start.  Please merge & commit it.  Are you planning to
write some tests & documentation for this new syntax?

The optimization wor (automagic probe disable/enable operations) will
be much bigger, and we should share the work.

- FChE