Change 'View on imgur' links to show the full imgur page, not just raw .gif.
Automatically refresh index both periodically, and when match not found.

The changes here work but are a bit messy. Will probably refactor later.
Move & rename links.js -> lib/lookup.js.
Fix problems with 404 error when ss not found.
Bump version to 0.2.0.
Merge pull request #4 from jimlloyd/feature/auto-refresh-index

Feature/auto refresh index