Android/IOIO: Add java files for voltage measurement.
Android/IOIO: New cpp and hpp files for voltage measurement.
Android: Support voltage measurement on IOIO board.
Merge branch 'master' of git://github.com/hjr/XCSoar
README, debian/control: add missing build-dependency on gettext
Android/Main: don't send resize to TopWindow before it gets created

Fixes nullptr dereference (TRAC #2575).
Android/Main: don't send pause/resume to TopWindow before it gets created

Fixes potential nullptr dereference (similar to TRAC #2575).
RowFormWidget: uniform row "available" checks in both loops

Previously, the checks for skipping unavailable rows were different
in the two loops inside UpdateLayout(), resulting in inconsistent
n_elastic counts, crashing the process with assertion failure (TRAC
#2533, #2538, #2562, #2563).
po: update German translation
po: update French translation
Manual airspace and flarm: More info on flarm details.
Manual glide computer: Improved formulation.