Various changes.

- Errors when accessing links are no longer logged as errors, but as
  verbose
- Accesses to non-reddit web pages now have a 1000ms timeout with the
  use of a separate function for urlopen()
- Code to test update mode in redditdownload.py added.
- Logging to a logfile now works, logfile path is dependent on user
  permissions
- DEFAULT_THREADS is now 3 (10 before), and DEFAULT_FLOOD_TIMEOUT now
  5000 (1000)
- The --quiet options is now assigned to a separate variable. Output
  control works like this:
  If debug is specified, ALL messages are written regardless of other
  options.
  If verbose is specified, verbose messages will be written, regardless
  of --quiet options
  If quiet is specified, only warnings, errors and critical errors
  will be reported.
- Debug messages added