DeviceBlackboard: explicitly cast enums to unsigned
AbortTask: add missing <vector> include
Makefile: remove duplicate CXX=clang assignment

Was in both llvm.mk and compile.mk.
po: update Japanese translation
po: update German translation
po: update Swedish translation
Makefile: move the "TESTING" flag to build/options.mk

Resolves a dependency problem: the variable was defined in android.mk,
but was used before that already in targets.mk.
debian/rules: add variable TARGET_OUTPUT_DIR

Allow overriding.
NEWS.txt: mention the new Kobo port
Form/List: fix pixel panning / e-paper check

This was the wrong way around.  D'oh!
release v6.7