Make order constant

This is a start to removing column major handling of matrices.
Remove order conditionals
Remove intermediate vars required for conditional order
Allow client to see which engine is registered
Forbid loading column major blas matrix

This may change. Perhaps we can have an allocating LoadBlas for column
major blas matrices. Thinking.
Merge mat64/la into mat64

This has been done to resolve a circular dependency issue that prevents
Norm(2) and Norm(-2) from being implemented.
Fill in minimal Norm(±2) code

We should be able to handle wide matrices, but this will come later.
Add test for Norm

Norm(±2) is, not surprisingly, difficult to pin down. The expected
values here agree with numpy well for Norm(2), less will with MATLAB
and the expectation for Norm(-2) is a fair amount (FWIW at this
magnitude) away from the numpy and MATLAB values which agree quite
well with each other.
Fixed Dot
Merge branch 'master' into vec