Small Speedup mapping ufuncs over DenseMatrix

Relates to #230. Not where we want to be, but it's a start. On my machine it speeds up operations on a 2048x2048 matrix from 25 to 16ms, in some cases. 

One really interesting thing to note: 

[info]                    MappingUfuncArray  4.89 =====
[info]              MappingUfuncArrayHarder 20.73 =======================

These are applying ufuncs to arrays. The *only* difference here is the complexity of the ufunc - I think one is inlined.