Added README and licensing informations
Ignore warnings related to sun.misc.Unsafe
Fixed null check on empty stack
Moved tests into a test package
Make it clearer that the 'offset' is the offset of the head element in the LFStack class
Added multithreaded tests on LFStack
Implemented size() operator for LFStack
Added javadoc to LFStack
Test stack.size()
Test contention on pop() for LFStack
Reduce the number of items added or the test will take very long to complete
Make node value immutable
stack head requires volatile as it's the target of CAS