travis: Add inital support

* Initial support for travis-ci.org
travis: Create build matrix for each target

* Build for each target
* Remove the `-j` flag due to each build VM only having "1.5" cores
Added initial version of JRPropo XBUS Mode B support.
travis: Use arm-none-eabi-gcc compiler

* Use the gcc-arm-none-eabi compiler.  This will cause Travis-CI to
  set the env variable `CC=gcc-arm-none-eabi` which would allow the
  Makefile to be simplified by not hardcoding `CC`
* "Travis CI VMs run on 1.5 virtual cores"
   http://docs.travis-ci.com/user/speeding-up-the-build/
   Use `-j2`
* Ask GCC to print it's version.  Travis-CI would do this automatically
  if there was a way to install gcc before `$CC --version` is
  automatically run.
Cleanup of code (whitespaces/defines etc). Added initial text for docs about XBus and its configurations.
Update Gps.md

made language more clear and consistent
Cleanup for coding standard.
Changed name of define to better name.
Merge pull request #235 from geekaz01d/patch-2

Update Gps.md
Merge pull request #224 from GruffyPuffy/xbus

Added initial version of JRPropo XBUS Mode B support.
Merge pull request #223 from kylemanna/travis

travis: Add inital support for travis-ci.org
Adding IRC notifications to the TravisCI configuration.
Updating readme.
Fix being unable to configure mixer via GUI.