k0.7.4
android/build: make NDKr13 happy
android/patches: add "0004-{abi}-link-prebuilt-staic-libraries-of-ffmepg.patch" update "0002-gradle-upgrade-build-tool-to-2.2.0-beta2.patch" fix an unpatch issue
android: migrate to Android Studio build system
build: build exo on travis-ci
android/compile-ijk.sh: fix typo
ijk-addr2line.sh
android: add script for ndk-stack