Feature Request: Icons for internal and external links

[ballaschk]

In the editor interface, small icons are displayed next to hyperlinks in the main text (envelopes next to mail addresses, chainlinks next to internal links, document sheets next to links to PDFs or DOCs).

Given the number of linked documents in the CMS, it would be nice to provide a clue wether a particular link leads to an internal/external site or a self-hosted document.