Data/Dialog/dlgChecklist_L.xml: Swap position of Prev/Next buttons

Use same arrangement as in the other dialogs.
Ticket #2515, XCSoar not shutting down on some CE devices due to buggy serial-driver.
Data/Dialog/dlgTaskPoint_L.xml: Swap position of Prev/Next buttons

Use same arrangement as in the other dialogs.
NEWS.txt: Added the changes made in 59b2e921aa3e6f8ce2226f80d52d1b415c40d61f
SerialPort: Code cleanup from 59b2e921aa3e6f8ce2226f80d52d1b415c40d61f (#2515).

Code verified to work on HP iPaq 314 (WM5).
Added ticket #2515 in NEWS.txt
Renderer/FinalGlideBarRenderer: Render with transparency on OPENGL targets
FeedFlyNetData: Fixed pressure_vario calculation

When the vario goes up the pressure obviously must go down...
Driver/FlyNet: Implemented WindowFilter for the vario value

This filter was suggested by the manufacturer and has proven to work well
for the device. The static pressure is now passed unfiltered as the filter
was only necessary to get the jitter out of the derived vario values.

This fixes ticket #2381
Device/Driver: Added gcc_override to AbstractDevice methods
Device/Driver: Moved AbstractDevice method implementations to source file
TrailRenderer: Fixed potential unsigned underflow bug
Merge branch 'v6.4.x'

Conflicts:
	src/Renderer/TrailRenderer.cpp
TrailRenderer: Extracted GetAltitudeColorIndex() function
Thread/Mutex: move attributes up
Thread: explicitly delete the copy constructor/assignment

Don't use the obsolete NonCopyable class.
Thread/PosixMutex: relicense to BSD 2-clause

This is pretty trivial code, and I'm effectively the only copyright
holder.
dlgTarget_L.xml: Help text for ETE.
Math/Angle: don't use optimised multiplication for Angle*fixed

Reverts the second part of e4b9b576.  Turns out that the
CatmullRomInterpolator does care a lot about the bits discarded by the
fast_mult() call, because it passes very small values (TRAC #2537).
The unfortunate bottom line is we can't predict the dynamics of the
two factors, and we must not discard any bit in the default operator
without knowing from where this was called.
RoutePolar: Optimized Initialise() method

The IndexToAngle() function performed a division, a multiplication and
a substraction for every call in the for loop of the Initialise() method.
This could be reduced to one constexpr constant and one substraction for
each iteration.
i18n: Make a few string translatable

Fix #3520