Mipea

Important:
Do *not* use this or older versions of the library. There is a bug which could disable wifi until a reboot in the gpio_clear_pud function.

- I2C:
- removes i2c_configure function and corresponding struct
- adds i2c_set_* functions to set the configuration
- SPI:
- removes chip enable from configuration struct
- adds extra function for configuring which chip enable line to use
- PWM:
- removes pwm channel from configuration struct
- adds the channel as parameter for pwm_configure

- adds I2C
- adds GNU autotools
- adds documentation using Sphinx
- bugfixes

- setup.py checks if mipea C library is present
- MANIFEST.in to include mipea C library in source distribution
- rename pud to pull

Features implemented:
- gpio.GPIO:
* set, clear, test, input, output, alternative functions, pullup / -down