Settings page enhancements

[fabiodrg]

Show some love to the options page. List of some ideas:

• Present extractors with a more human-readable name. Add a nice icon as well.
• Similar to parameters, the storage options could have a human readable text, rather than an identifier name.
• Remove the 'Reset all extractors' button. It is not implemented, as far as I know.
• Consider adding a "General" settings page that opens by default
  • Option to reset all extractors
  • Option to disable notification on new updates (Changelog Notification - Less intrusive #47)
  • Export/import settings
  • Resetting cache
  • ...
• Customisable order for the inputs in the options page. At the moment it will show textarea, text, checkboxes, .... If Create an interface to manage the extractors 'structure' #100 is implemented, could use insertion order?