List of changes

	Version 0.1 List works

	Version 0.2 Use Numpy arrays instead of lists for efficiency

	Version 0.3 Change the module interface to allocate more nlp instances instead of one
	now use nlp = pyipopt.create(xxx)
		and nlp.solve
			nlp.close()
	now we can create multiple instance of nlp. [Tested]

	Version 0.4 Move all the pointers to the 
	PyObject (callback function in Python) to the user_data field
	Therefore, the C callback function here can just dispatch it to the Python
	callable object in the user_data [DONE]
	[We wrap the user_data twice]

	Version 0.5: Bug in H matrix fixed

	Version 0.5.1: some stupid spelling error in the source file and comments fixed.

	Version 0.6: Fixed a memory leak problem (at least valgrind won't complain).

	Version 0.7: Fixed a bug for the value of m and n, a bug for reference counting.
	
	Version 0.8: Merged patches submitted by others, now supporting intermediate_callback (requires Ipopt>=3.9.1)

	Version 0.8.1: Updated the README doc. 

	Version 0.8.2: Merged a change from Guillaume Jacquenot, now there is no GOTO in the source code.
