Fixed chipKIT Pi's broken hardware interrupt pins. We now have working INT0 through INT4 on Arduino pins 10, 8, 3, 2 and 1.  (Note, the change in pins_arduino.h will affect all PPS based PIC32s for hardware interrupts. The rest of them should work now too.)
Merge pull request #415 from EmbeddedMan/master

Fixed chipKIT Pi's broken hardware interrupt pins.