Cleaned up .gitignore
Radiography-Detector finalized

Fully `pep8` and nearly full `pylint` conformity (I don't want to rename
all variables...)
Cleaning up description.
Cleaning up imports.
Bringing different options to the front of the file, so we don't have to
look for them.
Add lots of comments all around the place
Redo the final call to Fiji, so we can save the files as _average.tif
and _sum.tif in the end.
Updated instructions to install a recent DevSuite

These directions make it possible to have a recent, running version of
the official Aptina DevSuite on Ubuntu 12.04