change code style to jshttp

Right now we have 2 space indentation (`*.less`), 4 space indentation (`Gruntfile.js`) and tabs (`*.js`) all mixed up in the same project. So I've been thinking about fixing that for a while now. 

And while we're at it, could as well tweak other things (like one var per line) to conform to [this style guide](https://github.com/jshttp/style-guide/blob/master/javascript.md).

This commit will change almost every line in the source code. So if anybody is running forks of this project where those changes would be too hard to incorporate, I want to know about that.