adding swuart
sw uart rx and tx working
moving sw uart buffers to be global
gps init from js
swapping tm_uptime to timer3
adding nema parser
sw uart + nema parsing
removing sw_uart funcs
bump up sw FIFO to 256
fixed TC never matching MR[1]
cleaning up

removed needed checks

breaking gps init into gps-a2235h

adding newlines

changing floats to doubles

floats to double in hardware binding

adding headers to swuart
Merge #68 r=@tcr: software uart

Needs a lot of cleaning up still, though this works with the example code in https://github.com/tessel/gps-a2235h/pull/11

This PR does the following:
* Moves the uptime timer from Timer1 to Timer 3
* Timer 1 is now used for sw uart on port C
* adds hardcoded 9600 rx and 115200 tx
* adds nmea parsing code

Not part of this PR:
* multiple bitrates
* sw uart for GPIO port
* usable sw uart bindings to JS