changes from 0.08 to 0.09
=========================
* added priority parameter as suggested by Jason McCarver
* added parent/child callback parameters as suggested in a patch from
Knut-Olav Hoven (rt #70298)
changes from 0.07 to 0.08
=========================
* fixed bug where reading blank lines caused them to be skipped as
reported by Jason McCarver
changes from 0.06 to 0.07
=========================
* changed error handling if exec() fails to avoid problems with block eval
changes from 0.05 to 0.06
=========================
* added filehandle duping to reset STD* filenos in the child process
changes from 0.04 to 0.05
=========================
* fixed the order of filehandle processing in the child process
changes from 0.02 to 0.04
=========================
* fixed tests for better taint-mode handling
changes from 0.01 to 0.02
=========================
* documentation fixes