Merge pull request #94 from crealytics/master

Fix CompactHessian constructor invocation.
breeze 0.5.2
Rewrite ProjectedQuasiNewtonTest for better error messages.
Update SBT to 0.13.0
Remove unnecessary wrapper class.
Iterations in FirstOrderMinimizer start counting at 0.
More complicated test function for PQN.
Restrict test to an optimizable subset.
Simplify calculation of sigma.
Determine initial step size similar to Matlab version.
Fix: Add forgotten VectorMatchers.
Vectorize some calculations.
Instantiate SPG eagerly with Matlab-like parameters.
Use default PQN parameters from Matlab and pass max iterations to superclass.
Reimplement SPG as a transcript of Matlab version.
Renamed methods to be identical to ApproximateInverseHessian.
Gradient norm can be zero and Matlab doesn't do it either.
Set optTol to a reasonable value.