New renderer: Hide border intially

Referactored the tip renderer to be able to derive a new one:
This one does not display the borders at first
Merge pull request #20 from amenk/feature-renderer-tip-only

New renderer: Hide border intially

Ok, this is a really good one! I like this mode a lot. And the solution is so easy and straigt forward.Thank you. 

I like it that is way more unobstrusive. Though, there seem to be some minor css issues as a side effect from not having the .tpl-hint-border class in place
- the missing "overflow: hidden" makes some boxes appear as a straight. I'm not a css guru, but I guess that's the price we have to pay for not messing around with the original design
- the missing margin and padding has the effect that the border will appear as a solid line because all the the fading border of all parent elements is drawn on top of each other so that the fade effect is not visible anymore.

But even with these glitches this is still an awesome feature and totally worth merging! Thank you

Small idea: Using javascript we could detect the width and height and the position of the div and draw a new div with the correct border on top of that. This way we might be able to make it look nice without actually messing around. We would actually draw into a layer on top of the actual design. I remember I played around with that idea some time ago, but then I gave up because it wasn't trivial/. Still this idea is worth sharing, and maybe someone want's to come up with a new tip renderer mode that does that :)