Implement a subset of NumPy functions for omniscidb

[guilhermeleobas]

NumPy contains more than 500 functions listed in their website. We need to implement a subset of it. Ideally this subset should contain the most used NumPy functions.

• Reimplement numpy functions as python functions heavyai/rbc#31 contains a list of functions with the ones RBC already implements.

• Build a list of NumPy functions

[kcpevey]

We need an explicit list of required functions here. @dharhas

[pearu]

The existing list in heavyai/rbc#31 represents the current state best.

It will be a continuous effort to support more and more numpy functions / filter out numpy functions that support for omniscidb does not make sense.