useragents command doesn't create dupes
css parser uses bulk_create to store properties
changed scraper settings to improve performance
enable httpcache download middleware
Merge branch 'master' into improve-performance
fix minor issue in scrape command
add smart caching of requests/responses
add unique_together constraint to UrlContent
initial urls are now generated bounded to a user_agent
add webcache to .gitignore
Merge pull request #62 from mozilla/improve-performance

Improve performance