Added I2C and Analog
Also renamed spi files from spi.xyz to spi_test.xyz as having them
share a name with the SPI library in Python caused import issues.
Cleaned up a few of the other examples, but no major functional
changes to anything.
Merge branch 'master' of https://github.com/sparkfun/pcDuino

Conflicts:
	examples/SPI/spi.py
	examples/SPI/spi_test.cpp
	examples/gpio/gpio_test.py
	examples/hello_world/hello_world.py
	examples/serial_test/serial_test.py