platform/exp5438_2520: fix Msp430TimerMicroMap.

formerly, the map had T0A1 allocated for the SFDCapture.  But this moved
to T0A3 (in HplCC2520C).  But the MicroMap didn't change to reflect.
Fix it.
platform/exp5438_2591: PlatformPins shouldn't touch gp5

The dual chip 2520/2591 implementation has gp5 wired directly and the
MCU doesn't have it.  So don't initialize the non-existent pin.
platforms/exp5438_25{20,91}: clean up, remove various kruft
cc2520-v2: more clean up
cc2520-v2: add a window where pending interrupts can happen

Every iteration of processExceptions, we let pending interrupts occur
before actually starting to accessing the cc2520 chip.  This makes
this driver play better with other interrupt users.

We still also let interrupts in while spending time pulling bytes
from the RXFIFO (snarfMsg).  This hasn't changed.
add README for python/misc (serial port pkt observer)
add gdbinit files for exp5438_25{20,91}
add BootParams interface
tweak how platform_panic works (PANIC_KERN in panic.h)
finish adding Panic.hook for modules using Panic
exp5438_2520/2591: add support for _Build (build num) in target
exp5438_2520/2591: Change DEF_RFPOWER depending on presence of 2591
add Port7 to dumped h/w state
Msp430TimerP: update comment about h/w issues with Timer.overflow
exp5438_2520/2591: add BootParams
exp5438_2520/2591: modify PlatformCC2520P to use writePlatformRegisters
exp5438_2520: update RadioConfig comments
exp5438_2520/2591: add interrupt trace defines in platform_trace
exp5438_2591: update pin out table to reflect green led on 4.5
ffa/tp-master: update Repo_Notes and Development_Environment

- update major features (msp430 core and 2520/2591 driver)
- remove old integration branches
- move to Ubuntu 13.10 as default
- move keyserver to keyserver.ubuntu.com