Monitors MMFCE pools + minor improvements

- Monitors MMFCE pools and display the current balance in their
currencies (web page only)
- Display the current pool URL
- Don't send a warning email in the first 10 seconds (hashrate takes a
bit to get stable)
- Use a smaller font for the web page
- Ignore requests on /favicon.ico that most browsers send
- Faster shutdown with CTRL+C (within 1 second)