Add an option to refresh information for selected items

Add a menu item to refresh the information for all the selected items. This would open a dialog box with 3 options:

[Options list] Plugin to use
[Check box] Reuse plugin if any
[Check box] Always use first

The 1st option will contain a list of all the available plugins

If the 2nd one is checked, the same plugin as the one already used will be re-used. This will be done by comparing the stored URL with the one returned by a plugin (the same process is already done when using drag-n-drop from a web browser). If it's unchecked, then the explicit plugin will be used in any case.

The 3rd option is used as for the plugin to import from an item list. When a web search returns more than one result, there are 2 options. If the box is checked, the 1st result will be used. If it's not, a dialog ask the user which one should be used.