Add support for Less Neglect

Hi there!

Here's a service provider integration for Less Neglect. Our API reference is [here](http://beta.lessneglect.com/api/clients#javascript).

I've successfully tested with the awesome JS test setup you are guys are using as well as ran a local version of analytics.js with the Less Neglect changes and it works well. Please let me know if I missed anything in the pull request.

LN logos:
http://f.cl.ly/items/1C36190V082I263L3d45/ln-light-background.png
http://f.cl.ly/items/3s281o353g1A0a2N3d26/ln-mark-300dpi-cmyk.png

Big thanks to @reinpk for helping me work out some kinks this weekend.

Cheers,

Billy Coover
Less Neglect