Adding trig functions for angle calculations

[heygrady]

http://github.com/nex3/sass/issues/issue/4/

In order to target IE-specific fixes with handy mixins, it is necessary to do some simple math that is not supported currently in SASS.

Potential uses:

• IE specific fixes like calculating the shadow angle from the css compliant offsets.
• Working with CSS transforms

[thedarkone]

I use trig functions for pure CSS ribbons (allows me to change the angle without having to manually recalculate border dimensions).

Here's my implementation: http://gist.github.com/609458.

[chriseppstein]

Added trigonometry functions for fun and profit.
Closed by 463301e.

[heygrady]

hawt. I will do something incredibly useless with this new functionality.