clickable links in chat

[julianseeger]

extracted from #519

Text is now copyable (as soon as #519 is implemented), so links can be copied into the browser, but clickable links would be far better in terms of usability. Unfortunately, that feature is harder to implement than just selecting text (which was achieved by replacing the Label by a styled TextArea) so it was split out of the original ticket.

(needs to be discussed in terms of future enhancements ... images, code, citations, etc.)

[julianseeger]

http://fxexperience.com/controlsfx/features/
search for the HyperlinkLabel and done ...

[thechauffeur]

While both (see #519) are important it would be nice to have either one option ASAP. Whichever is less pain to implement.