Added documentation for ardrone navigation data.
Fixed typo and updated options description for navdata
Added NavOptionDemo and NavOptionVisionDetect references.
Added how to install ruby to getting started and fixed typoe in ardrone navigation driver docs.
Added Info for how to isntall rubinius when concurrency is needed.
Fixes typo on attribute for anchor.
Changed docs default ruby installation to use RVM.
Adding new events to ardrone navigation and updating layout.
Added animate method to docs and updated led method options.
Merge pull request #44 from hybridgroup/ardrone-nav-data-docs

Added documentation for ardrone navigation data.