test/RunFlyingComputer: new debug program
test/DebugReplayIGC: don't ignore invalid GPS fixes

Pass them to the application instead of skipping them.
po: update Italian translation
po: update Polish translation
po: update French translation
Manual de Blitz: Next generation German short intro to XC.
Makefile: add variable "TARGET_IS_ARM"
Makefile: add option "GLES"

Use OpenGL/ES on by default on all ARM devices, including the
Cubieboard.
Makefile: disable GLES on Cubieboard for now

This requires some more glue code to combine SDL with GLES.  Later.
release v6.6
android.mk: Simplified NATIVE_HEADERS dependencies
android.mk: Pass cache setting to submakes
NEWS: prepare for 6.6.1
VERSION.txt, NEWS.txt: prepare version 6.7
Implement contour lines on terrain, closes #2451
Makefile: link harness.a with src/Audio/VegaVoiceSettings.cpp

Fixes linker failures.
po: update Polish translation
po: update German translation
po: update xcsoar.pot
Util/Macros: fix guard macro name