3.4.x.g2

 * Includes the changes in 3.4.x.g, but reimplemented
 * Android Studio support. (see also #18) ADT is still supported, only aidl files moved and AndroidManifest.xml duplicated. When ADT support is dropped, move directories and update app/build.gradle
 * Unconfigured keys are not handled at all. Note that there is no check if there actually is any mapping for the key, that would require a config change to support combo.
 * Keep original KeyEvent for default dispatching
 * Allow external devices by default - some devices identify normal buttons as external
 * SeekBarPreference corrections