InfoBoxes/Factory: don't translate the "deprecated" text

Don't add useless work for translators.
po: update German translation
po: update French translation
po: update xcsoar.pot
Tracking/SkyLines: define a protocol for querying user names

The traffic list dialog now shows the user's display name instead of
the internal user id.
Computer/StatsComputer: Fix logic to handle location jumps

Once a single location jump was detected the calculation of stats never
resumed.
Tracking/SkyLines: check HAVE_SKYLINES_TRACKING_HANDLER, not HAVE_POSIX
InfoBoxes/.../Factory.cpp: Harmonized Captions for Atlitude, Height and Elevation.
Panels/GlideComputerConfigPanel.cpp. Caption change L/D to GR.