merge the lowpower stuff from my devel branch
*actually* enbale WFI_IDLE
faster code means we get to sleep earlier. co-operative scheduling for same-priority makes kernel simpler and faster
document how to work with SWD with WFI_IDLE enabled
merging RTC helpers from my experimental branch
merging RTC helpers from my experimental branch, these go pretty much hand-in-hand with the lowpower stuff
Do not block on _DEBUG() when USB is not connected.
fix I2C pinmux
quick shell command to test the I2C by reading the accelerometer
some notes about where to place the i2c variables currently in main global scope
Update Chibios 2.6.x stable
Update Makefile to match current 2.6.x demos
Add motion detection support for MMA8652FC.
main: Add a command for driving the accelerometer.

Rename the test command "acc" to "accread".
main: Blink led quickly when detection motion.