added alt-text support, and alt text formatting

When the user hovers (with his mouse) over the `<span>...</span>` element, a formatted string containing the time stamp is shown using the `LLLL` format.

The user can also provide a format him/herself using the `livestampaltformat` attribute.

When the `title`-element of the `<span>` tag is modified, a `change.title` event is risen as well...

The code is not yet minimized to allow fast editing.