Ignore the endianess markers in Numpy dtype strings - #1855

Doesn't need changelog entry. This fixes a bug in an unreleased feature (doctest testing).

@olebole: Are you able to test this branch on the big endian platforms, or should I just merge and let it propagate out and cross our fingers?

I could test it (in the context of a package build), but the patch does not apply to 0.3.0.?

That's true -- the doctesting was significantly reworked post 0.3.0... It will take some work to get this on 0.3.0, or we can just wait until 0.3.1, I guess.

I have no problem to help by just crossing fingers and uploading 0.3.1 ;-)
Is there a plan to release it soon?

I don't think we have any 0.3.1 plans at the moment, but I'm sure there will be one...

I'm going to merge this, as I think it's mostly harmless on little endian machines and might fix things on big endian machines.