More more more

* Can apply to iterable function (aka, juxt)
* Added `juxtM`
* Added `index`
* Added `mapVal` and `mapValM`
* Added proper `mapM` and renamed old to more accurate `lift`
* Better support for Promise polyfills in `pure`
* Added `arrayM`
* Added `Maybe.try`
* Change indexed methods to `at`, `get` and `has`.
* Rewrote bench runner