This is another iteration on improving the infamous
>The `libsass` binding was not found

Messages will now provide more useful information which will
- give users a chance to resolve the problem themselves
- give us more debug information from the error message alone

Error messages produce now will look like:

>Node Sass does not yet support your current environment: OS X 64-bit with Node.js 4.x
>For more information on which environments are supported please see:
>http://....

>Node Sass could not find a binding for your current environment: OS X 64-bit with Node.js 4.x
>Found bindings for the following environments:
>  - OS X 64-bit with io.js 3.x
>  - OS X 64-bit with Node.js 5.x
>This usually happens because your environment has changed since running `npm install`.
>Run `npm rebuild node-sass` to build the binding for your current environment.

>Node Sass could not find a binding for your current environment: OS X 64-bit with Node.js 4.x
>This usually happens because your environment has changed since running `npm install`.
>Run `npm rebuild node-sass` to build the binding for your current environment.