MKL/non-MKL Reconciliation

After no short journey, the port of Caffe away from MKL has come full circle and is ready for integration.

Chronicle:

- boost/eigen3 port of Caffe started by @rodrigob, carried forward by @kloudkl, then fixed up by Alejandro Dubrovsky and @jeffdonahue.
- A boost + openblas alternative was tried and our options weighed.
- Rowland Depp emerges from the shadows with a brilliant commit 56b8ca0 to settle the issue.

There could be dragons here. #122 is a sure problem, though it is addressed by #152 . I vote #163 be merged before this so it can be easily migrated to master, but another lint pass will need to be done.

I have made this PR from BVLC/boost-eigen so that we can polish this together for this glorious merge.