Glide.hpp: add comment
GlideComputerAirData.hpp: add comment
GlideRatioComputer.cpp: display ^^^ while circling

It was displaying the last GR before entering the thermal
InfoBoxes/Factory.cpp: update help for GRAvg

Don't say "in system setup" - it can be configured by clicking
the infobox
GrAverage.cpp: add 7 second option for paragliders using brake
AltitudeSimulatorFullScreen.cpp: rename to AltitudeSimulator.cpp/hpp

Also refactor the class name to AltitudeSimulatorPanel
Panel/Altitude, Sim.cpp: option to show/hide second set of altitude units
GlideRatioFormatter.cpp: only show decimal if fabs(gr) < 10

was not using fabs() function in test
Version bump 2.0.4_beta