objc: intro the FFI with Objective-C

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib: intro the cocoa library

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
objc: intro tests

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
tests: clean up java debug prints from tests.sh

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>