Allow specifying "title" even when not showing the label

[Robyer]

Each icon's element should have title="{custom title}" tag. And input for this custom title should be visible in wp-admin even if "Show icons labels?" is unchecked.

Also I think I saw that icons has the alt="..." text, which was set to default name of the icon. It should be imho set to the same value as the title, because if plugin user chooses to use some icon for different service (e.g. use Skype icon for Steam - doesn't matter, just to explain this), it shouldn't "leak" that this icon is in fact Skype, it should say everywhere that it is "Steam" if user named the item that way.