[Arm-netbook] laptop power board

[Luke Kenneth Casson Leighton]

.... i have the LTC 4155 15W power IC as well as the STC3115 battery
monitor ICs recognised on the I2C bus with 5V power applied, yippeee.
embarrassingly, i had the 5V DC socket wired reverse-polarity.  this
is, uhh, an officially-sanctioned test of the reverse-voltage
protection on the power board design.  no, really :)

on a 2nd (minimally-populated) board i have the 5V regulated output
up, but not on the fully-populated board.  what i'll do is fill in all
the components from the minimally-populated board, testing it as i go
along.

i'm looking forward to _not_ setting fire to the apartment when i plug
in the e-bike lithium battery.  unlike many of these "laptop"
batteries it has no current protection circuit built-in, and it's
perfectly capable of delivering 20 amps maximum current :)

l.