Jump to declaration UI

[Vladimir Prus]

Eclipse has a slick UI for jump to declaration -- if you press Ctrl, and
hover a mouse over a symbol, it turns into a hyperlink, and clicking it gets
you to the symbol. This seems hugely convenientl, and I'd like to implement
same. Objections?

And while we're at it, does Kate support either clickable links directly,
or making a block of text look like a clickable link?

- Volodya