added sensibly greater options and reorganised alphabetically

* reorganised alphabetically to make maintenance easier.
* updated several gradient styles.
* added sensible options to all mixins so that they are not just copy
pasting code and can be customised easily.
* added some quick examples based on my personal grid system
* made sure it works with less 1.1.4

Realise you may wish to keep your project as is, but figure would give you a heads up on what I have done. Any questions feel free to ask.