Fixes to make flight engineer use correct gravity and velocity
minor tweaks
Merge pull request #5 from Gerry1135/simvelocity

Fix for velocity thrust correction (issue #4)
Fixed issues with IntakeAir readouts.
Fixed bug where actual thrust does not update to 0 for deactivated atmospheric engines.
Prep for 1.0.7.1 release.
Added relatives speed/velocity & units helper.
Update unit helpers.
Added IntakeAir Usage readout.
Altered angle helper.
Fixed an issue with deltaV not calculating in flight.
Fixed NullRef whilst loading the action menu.
Release version 1.0.8