Second prototype sent to fab

Many of the initial assembled r0 prototypes had shorts on I2C bus:

#33

We believe this is because of bad footprint for U5 (the 9DoF). I removed U5 from my prototype and the bus is no longer shorted.

I have ordered new 2x2 panel from OSH Park and new stencil from OSH Stencils. SparkFun should have by the end of the week.

The commit version that was ordered is:
84d48e1

First protos sent to fab

Merge pull request #24 from wyolum/master

better raytraced renders