Add enrich_location to Smithsonian pipeline
Added docstrings and comments to fetcher.py
Added -e switch to sed invocation in fetcher.py

This is necessary for a POSIX-compliant sed, per the following:
http://hintsforums.macworld.com/showpost.php?s=ec7ef3b84f662427f80d52db67dd8404&p=499844&postcount=2
Merge branch 'develop' of https://github.com/markbreedlove/ingestion into develop