Translated using Weblate (German)

Currently translated at 80.5% (54 of 67 strings)
check maven version
Translated using Weblate (French)

Currently translated at 1.4% (1 of 67 strings)
Translated using Weblate (German)

Currently translated at 79.1% (53 of 67 strings)
Translated using Weblate (Spanish)

Currently translated at 1.4% (1 of 67 strings)
Merge remote-tracking branch 'origin/master'
Translated using Weblate (German)

Currently translated at 100.0% (67 of 67 strings)
fix German translation [skip ci]
fix German translation, remove context [skip ci]
update android build tools to 19.0.1
add maven version check to start of before_install script
Translated using Weblate (German)

Currently translated at 92.5% (62 of 67 strings)
Merge remote-tracking branch 'origin/master'
Merge branch 'master' into coordinates
implement getPolarCoordinate, issue #78
test should use constructor, issue #78