added mapbox provider dpmap implementation.
code cleanup.
increase features of the map interface.
cleaned up dp map interface.
Doesn't crash when can't access usb device.
Use the correct Math method to calculate a hypotenuse.
Added method to calculate the 3D distance between two points
Added unit test for the new 3D distance method
Merge pull request #943 from arthurbenemann/3Ddistance

3D distance
Fix eclipse build

When building with the eclipse the app would be creeated as desired, but would crash when trying to open in a real device. This fix this issue, but it makes CORE project not reachable via the eclipse navigation tools anymore as was done in #939.
Merge pull request #945 from arthurbenemann/eclipseBuildFix

Fix eclipse build
Make eclipse 'Open Declaration' point to the Core source instead of compiled jar

Fix thanks to http://stackoverflow.com/a/12891499/2577890
Merge pull request #946 from arthurbenemann/eclipseNavigation

Make eclipse 'Open Declaration' point to the Core source
Moved the ROI class
Update references broken by previus commit.
Merge pull request #947 from arthurbenemann/refactorROIclass

Refactor ROI class
Simplifying the follow-modes.

Development of the modes will be made on a separate branch.
Simplifying the ROI class.
Merge pull request #948 from arthurbenemann/follow-simplify

Follow Simplification
Merge pull request #954 from squilter/issue_803

#803: Doesn't crash when can't access usb device.