- CMake should be used from Android SDK. Personally I had issues using CMake from my OS (Ubuntu)
- minimum version of Android NDK must be 15c, as build target API level 26 is not supported on earlier releases
- removed ABIs that are unsupported in recent NDK and also not build by default
@akallabeth thank you for pointing out that I was using the wrong CMake version.
* increase minimum required SDK to 14
* change functions from void to BOOL where required to have proper
return values
* update the JAVA classes and JNI accordingly
* add return value checks for *alloc and strdup
