GCS/Colibri: make board image tarnsparent backgroudn

Looks much better on bootloader.
PiOS MPU6000: add support for placing on bottom of board

Colibri mounts the sensors on the bottom, so this adds those
options to the configuration.
PiOS MPU9150: support positioning on bottom of board

This is for consistency with the new cases handled
by the MPU60X0 class of drivers.
PiOS MPU6050: add support for placing on bottom of board
Colibri: correct sensor orientation
Colibri: disable SBUS inverter when not used

This allows Spektrum or PPM to work on USART2
TauLabs Development Enviornment

* Docker based Fedora 20 build container, including:
  - GCC ARM None EABI 4.8 2013q4 (Makefile)
  - GCC 4.8 toolchain i686/x86_64 + C++ support (Fedora)
  - Qt5 Development libraries/headers (Fedora)
  - Java 1.8 OpenJDK (Fedora)
  - libusb (Fedora)
  - libudev via systemd-devel (Fedora)
  - Google Test (Fedora)
  - astyle
  - make, wget, git, bzip2, expect

* Creates and uses 'taulabs' user. Operates in /taulabs. Use 'docker cp'
  to fetch artifacts from the container.
* Includes expect script for unattended Android SDK installation. Please
  don't sue me.