Add a very simple function to return the Python API number

[Martyn Gigg]

It will simply be this

def apiVersion():
    """Indicates that this is version 2
    of the API
    """
    return 2

The old one will return 1

Users can then more easily tell which api is currently active in their environment

[Martyn Gigg]

Refs #4723. Add apiVersion function.

Users can then more easily tell which is currently active.

Changeset: cbffd8e4ae2de4360a6c7ff15a2965be0fb11ce7

[Stuart Campbell]

Does indeed return a 2 by default, then if I run:

from mantidsimple import *

then it returns a 1.

[Stuart Campbell]

This ticket has been transferred to github issue ​5570