ExternalLogger.cpp: fix crash if download flight before logs folder exists

This only causes a problem if the internal logger has never created
the 'logs' folder.
MapOverlayButton.cpp: draw white background behind subscript, line two text

On the screens button, "Auto" etc will have a white background
ButtonLook: add "dimmed" state of button

Used for making a button less obtrusive
ButtonRenderer.cpp: add "dimmed" bool parameter

uses dimmed button state for non-pushed button when true
MapOverlayButton.cpp: draw background around line2, subscript of button

Makes line 2 text more visible
MapOverlayButton.cpp: draw dimmed button when flying

This way the buttons are very clear at startup, but during flight,
they dim a little so the pilot can focus more on the map
InfoBoxesConfigPanel.cpp: update help text for Use final glide mode
TextInBox.cpp: remove GLBLEND

Blending the background made the labels harder to read.
InfoBoxes/Panel/MacCreadyEdit.cpp: fix truncation of final glide altitude
InfoBoxes/Panel/AltitudeSimulatorFullScreen.cpp: fix truncation of final glide altitude
MapOverlayButton.cpp: use TextInBox to write outlined Text

This is used for the buttons with one symbol (S, M, +, -).  The symbol
is more visible in both light and dark backgrounds this way.
NEWS.txt