Updated 'list' commands. (issue #300, #308)

- Updated Storage.getTop3() methods to take in channel parameter to pass
  into queries
- Updated 'list' commands to only show reports for the specified channel
  when not in 'globalstats' mode
- Moved Storage.getEditTop3() to a more logical location
Updated 'show' commands when no number is given.

- Simplified the 'show' commands to call their corresponding 'list'
  commands when no number is given so their behaviours are synchronized