Added pioctl op and PIO_pioctl API call. General purpose op for IO manipulation in tradition of UNIX ioctl call.
This will be the interface for doing all sorts of IO layer stuff such as buffering, blocking, async, etc. At least until someone has a better way to do it.
Also added record separator field to ParrotIO object and allow changing from default \n. Needs finishing so we can support setting recsep to NULL for slurp mode. Currently tests fail if I set to linebuf by default.
-Melvin
