Add description field where user can give additional information to bookmark

[DaniloNovakovic]

It would be great if the user could provide additional information somewhere to bookmark (ex. instead of having just the link and regexp, it would be good if he could have a description describing what the site URL is linking to is about)

Since, in my opinion, the widgets in popup window are taking enough space as it is (and will be even more once I add the ability to chose a parent folder where BM should be saved), this description field should be only available through Bookmark Manager (ex. in Edit window)

Additionally, this field should have a limit of around 100-200 characters so that the user doesn't exceed the allowed size of the local/sync storage