GaugeVario: Fixed typo

Apparently this typo has been there from the start of the OpenGL
implementation and nobody noticed it.

The bugs display needs to be redrawn if either the bugs value has changed or
the canvas is NOT persistent. With the previous behavior the bugs were only
drawn if they changed on backends with a non-persistent canvas.

See commit 4965c22952dab33d30bd7af8dc16eeb24c5f4f73
Driver/GTAltimeter: Fixed vario parsing

This should have been the non-compensated vario value from the beginning.
I must have confused netto for non-compensated back then...
Sorry about that!
Manual data_files: Typo.
Merge remote-tracking branches 'turbo/v6.4.x' and 'hjr/v6.4.x' into v6.4.x
GaugeVario: Applied naming convention
XSRenderer: Increase the number of terrain slices on fast hardware
Dialogs/Device/FLARM: Reduce number of menu entries of FLARM range config

The 100m resolution created 235 menu entries. 250m reduces this to 94
entries.
Wording modification: "Unreachable through terrain." into "Unreachable due to terrain.".
{Gesture,Kinetic}Manager: move code to UIUtil/
test/DebugReplay: clear time_available on HFDTE
UtilsSettings: remove unused flags
Protection: move variables to UtilsSettings.hpp
Look/Fonts: Flush text cache after resizing InfoBox fonts
Formatter/TimeFormatter: Indicate usage of mm:ss format for short timeframes

From a value like "05:03" it is not immediately obvious if this means
"5 hours + 3 minutes" or "5 minutes + 3 seconds". The only visual indication
in xcsoar's infoboxes is the appearance of the seconds in the infobox
comment field if the former is shown. However for short time-frames
the missing second is easily missed. Try to improve the situation
by separating minutes and seconds with "'" for short time-frames.

Signed-off-by: Andreas Pfaller <pfaller@gmail.com>
Screen/Fonts: Flush text cache after resizing InfoBox fonts
Math/Kalmanfilter1d: Use smaller p_abs_abs_ when resetting. A value of 1e10 causes range problems.
android/I2Cbaro: use EOC pin when possible.
Data/Dialogs: Unify layout of prev/next buttons for page switching

Implements first part of ticket #2513.
TraceHistoryRenderer: Simplified sgn() function

This makes it possible to declare the function as constexpr
TraceHistoryRenderer: Make sgn() function constexpr