Merge pull request #12 from DaveDeCaprio/master

Fixed bug in DenseMatrix collapse by Row
Merge branch 'master' of https://github.com/DaveDeCaprio/breeze
we can use MutableInnerProductSpace in LBFGS
bug fix to Scaling#sumArrays. 

You have to differ by 2 scaleConstants + numMantissaBits before you can safely short-circuit.
Fixes #30: Shaped solve of transposed and slice matrix does not work