added gitignore
added agileofx board, Cortex-M3

changed make term to miniterm.py with 115200 baud on ttyUSB2
clock is driven by pll on a 16MHz quartz
using vtimer instead of busywait in at86rf231 driver
import of @AlaeddineWeslati's agilefox port with fixes addressing @OlegHahm's comments in https://github.com/RIOT-OS/thirdparty_boards/pull/2