Transformers have been added to the prefilter.
Transformers have been added to the prefilter.

Transformers are run first before the checkers/handlers and
simple transform lines of input.  In the long run, we are going
to move away from checkers/handlers and just use transformers.

The new transformers are used to implement the a=!ls and b=%who
syntax.

ipython/ipython,ipython/ipython