Feature request: Negating --keep-order

[Rasmus Villemoes]

Hi,

First, thanks a lot for GNU Parallel. It is really nice to work with.

I have a wrapper script which ends up invoking parallel. One of the
flags it passes to parallel by default is --keep-order, since that's
generally what I want in this application. However, the wrapper also has
a facility for passing on options to parallel, and sometimes I might
want the default behaviour. So I would like to be able to pass
--no-keep-order in order to override an earlier --keep-order. 

There might be other boolean flags it could be nice to negate, but so
far this is the only one I've had a use case for.


Best,
Rasmus