First addition of dsPIC33F/PIC24H chip family programmer!

First addition of dsPIC33F/PIC24H chip family programmer!
See README under firmware/apps/pic for details.

Note that it has only been tested on dsPIC33FJ128GP708 (and
x710) chips and lacks some functionality and documentation.

Added optional timeout argument to GoodFET client class
serInit method. This is passed along to the serial object.

To build my dsPIC33F/PIC24H related app, define
INSTALL_PIC_APP somewhere near the top of goodfet.c and add
apps/pic/dspic33f.o to the firmware Makefile.

Added new timing routines that use Timer A to count
milliseconds, microseconds and clock ticks. These overshoot by
a few instructions, and may need refinements as research
demands.

Fixed minor typos in comments of a few source files.

git-svn-id: https://svn.code.sf.net/p/goodfet/code/trunk@452 12e2690d-a6be-4b82-a7b7-67c4a43b65c8