android: android build first draft: - added buildozer.spec - added src/sat.conf which is the configuration used on android (FIXME: need to rename/move it) - small hack to change loading paths on android - sys.platform is set to android when kivy_utils.platform is set to android - softinput_mode is set to "below_target", so field are not hidden when virtual keyboard appears Note: using org.goffi.cagou instead of org.salut-a-toi.cagou for package domain because the dash ("-") is causing trouble to buildozer. This need to be fixed.