Hyperbolic Module

TODO:

- [ ] sinh
- [ ] cosh
- [ ] tanh
- [ ] coth
- [ ] asinh
- [ ] acosh
- [ ] atanh
- [ ] acoth
@certik `sinh(x)` can be simplified to `(e^x - e^{-x})/2`
should we perform this simplification in the `sinh` function itself or add some `expand` function and do it in there?