Reading Annotation Volume as 16-bit, not 32-bit uints

[dgoodwin208]

I think there is a subtle issue with the foldchange.py example

In the api documentation the annotation volume is listed at as a 32-bit uint:
http://help.brain-map.org/display/mousebrain/API

But in the foldchange code, the data is loaded from the zip with the 'H' (unsigned short, 16-bit) designation.

I was running around in circles trying to figure out why the annot variable in the main() was twice as long as the gene-specific data. I believe this is the issue.

The solution is easy: change "arr = array.array('H', raw)" to arr = array.array('I', raw) in the DownloadAnnotationVolume() function
(reference: http://docs.python.org/2/library/array.html)