Write images to file correctly under windows
Ignore .egg files & dir generated by setup.py
Detect windows and write binary file

http://stackoverflow.com/questions/6552121/how-to-download-files-over-http-via-python-urllib2-correctly
Forgot brackets in last commit
Remove need for platform package

Deleted unncessary comments (don't even remember what "Why no comments
was about?", didn't mean to commit that, sorry...).

Removed platform-dependent file opening.  Using 'wb' mode should be fine
for all platforms according to docs, especially because only opening
file for writing here.

Closed file after writing.
Merge pull request #37 from CnrLwlss/master

Writing images to file as binaries under windows (and .gitignoring .egg files generated by setup.py)