[FIX] AttributeError: HTTPResponse instance has no attribute 'tell'

Python gzip cannot handle streams. So bad...
Solution from: http://rationalpie.wordpress.com/2010/06/02/python-streaming-gzip-decompression/
Merge pull request #82 from alanjds/gzip_support

[FIX] AttributeError: HTTPResponse instance has no attribute 'tell'