Targets SDK 26 as required by the playstore.
Fixes screen auto-rotation closing game.
Hides on-screen navigation bar if present.
Update gradlew.
Fix display aspect on 18+/:9 displays (like a Samsung Galaxy S9).
Remove small app icons, not required.
Fix xml in unpacking activity.
Support Android permission: On Android 6.0+ you need to manually give write
permission (as required by google).
Background during unpacking (just a demo for now).
Material Design: no more Android 2 interface.
Immersive mode (Android 4.4+ - hide NavBar for fullscreen mode).
Also resync properly the dependencies versions.
Don't let the makefile handle the cleanups itself. Let gradle do it.
This is one of the first steps to remove the makefile and replace it with a full gradle support
This little update is due to a packaging problem when uploading on play store. They don't permit to re upload an APK with same version code.
This case was a fail on openssl packaged version which was old and rejected by Google but they don't remove the APK then i should increase the version code to permit having it on play store
The old Ant build system has been deprecated for a while and new development is focused on Gradle.
I also removed a hardcoded string that lint caught and moved the patch files to a subdirectory.
I left the JNI files in the root directory.
