rename JNIContext to KernelContext, introduce new JNI methods
replace initJNI by initKernelRunnerJNI & initKernelJNI, introduce a new KernelRunnerContext class on native side
replace initJNI by initKernelRunnerJNI & initKernelJNI, introduce a new KernelRunnerContext class on native side
implement restructured JNI methods
final restructuring, better performance in BufferManager, replaced list by vectors (better performance)