Fixed validation error by updating jQuery from 1.7.2 to 3.1.1

- Added print facility
- Changed date formatting, made it less confusing
- Fixed compatibility issue with Folder Pane View Switcher add-on

- Note area is completely redesigned. Now it's html.
- Removed annoying 'Save' button. The save is automatic now.
- Added possibility to tag notes which have notes.
- Added status panel. Errors are reported through the panel, but not through the button as it was before.
- Changed context menus.
- Changed default note status icons and the way of their customization.

- code clean up
- button icons are changed