Add less support

**Testing Generated CSS**
`grunt` now tests to ensure the generated LESS and SASS css files match.  If they do not match, then grunt will throw a warning and abort the build.  You also get a pretty view of the css differences:

![image](https://cloud.githubusercontent.com/assets/5067638/4785542/5eae674a-5d80-11e4-9c5e-14ec55d9dc05.png)

**README.md**
I initially fixed a couple typos and added some syntax highlighting, then got a little carried away on prettifying the readme.  Let me know if you want to revert anything back to the original verbiage or layout.  Here is the [updated readme](https://github.com/tameraydin/ngToast/blob/4733e4fa264c362481be205f035e9481ca60cde9/README.md).