Created direct LBFGS approximate Hessian.

Created a class in lbfgs.py that computes matrix-vector products with the LBFGS approximate Hessian directly, not its inverse.
Also added a dummy class in bqp.py for compatibility with older python versions. (This should be moved to the utilities section of the code for broader applicability.)
Fixed bug and tested DirectLBFGS.

LBFGS now runs correctly when compared to Inverse LBFGS.
Applying matvecs to an arbitrary vector first with inverse, then with direct BFGS approximations yields the original vector.
Added Inverse LDFP class based on new LBFGS class.

Also, fixed naming convention: LBFGS class is simply "LBFGS" instead of "DirectLBFGS"
Migrated in augmented Lagrangian and matrix-free NLP.

Migrated new files from a personal hg repository and updated links to other
NLPy files. Also, added a restart function to InverseLBFGS to allow possible
restarting of the approximation e.g. in subproblem solves.
Added test of aug. Lag. problem class.

Test of augmented Lagrangian form of NLP passed successfully.
Commit includes several bug fixes to mfnlp.py and auglag.py.
Fixed Hessian-vector product error.

Fixed code based on a mistake in the derivation of the Hessian of the
augmented Lagrangian.
Small bugfix in lbfgs.py

Fixed a small counting error in LBFGS class within matvec calculation.
Added LSR1 quasi-Newton approximation.

LSR1 approximation has been created, but is yet to be tested.
Add build info for OSX.
Improve error message.
Rename README for OSX.
Simple adjustments to perf profiles.
New simpler profile tool.
Merge branch 'pprof_noma' into develop
New licensing: LGPLv3.
Add target to LGPL icon.
Adjust dominating performance profile.

If a solver consistently dominates the others, its ratio array is
constant. This causes no horizontal line to appear on the plot. Fix this
by moving the last abscissa to xmax.
Fix bug in vertical range of pprof2.
Draw tail in perf profiles.
Improvements to pprof2.

- Now returns a set of axes instead of showing the plot,
- make sure to create a fresh set of axes at each call.