incorrectly imports big-endian 16bit uints

[GoogleCodeExporter]

What steps will reproduce the problem?
1. load data from a big-endian uint16 file

What is the expected output? What do you see instead?

It looks like the bytes are not swapped so the returned values are in the bit 
order ([8, 9, .. 15, 0, 1, ... 7]).  

There is already a function `IsByteSwapped` which will determine if the swap is 
needed.  

What version of the product are you using? On what operating system?

 master, linux

See test images at 
https://github.com/soft-matter/pims/blob/master/pims/tests/data/stuck.tif

Original issue reported on code.google.com by [email protected] on 28 Jan 2014 at 3:23