Allow transformation of multiple points at same time

[JeremyBYU]

Pyrproj allows you to transform multiple points at the same time. If you have a lot of points I think this may be much faster than just looping through a list of points (in python) and making a c-api call every time.

Not sure if it will make a difference in speed to other modules using bpyproj. We should possibly determine/consider if we should add this.

[vvoovv]

I am unlikely to use that feature.