Merge pull request #18 from ahcorde/master

es: Fix the hardware structure
es: ROS documentation
es: ros documentation
PXF setup complete, ROS in Debian installed and working
es: Ros documentation
Merge pull request #19 from ahcorde/develop

es: ros documentation
AP_HAL_Linux update
Add board2.png to hardware
put right path for board2 image
Rearrange PXF paths
Merge pull request #20 from ahcorde/develop

es: Ros documentation