Updated test code to download a new consensus document each time.
Added print statements for debugging.
Added comment with potential solution to zlib error in the _get_remote_document() method.
Moved Zlib decompression logic from docdownloader.py's children to docdownloader.py
Updated code to redownload compressed documents if a decompression failure occurs.
Updated comments and log messages.
started migration of full codebase to using immutable cells
Merge branch 'NetstatusZLib' into ImmutableCells