[WIP] Rewriting the Univariate Solver

This PR aims to rewrite a cleaner and robust univariate equation solver.
- [x] polynomial
- [x] rational
- [x] trigonometric
- [ ] functions solvable by LambertW
- [ ] write 4 tests to complete coverage
- [ ] correct typo
On Tue, Oct 28, 2014 at 11:31:08AM -0700, Harsh Gupta wrote:
>    <expr>.match can return None if no match is found but I'm not able to find
>    an example for our particular pattern.

I don't think there are.