Fix a bug in newest versions of JQuery

I don't know if it is coffee or jquery related, but in newest versions of jquery, Invoking literallycanvas throwed errors like this one : ```Error: Syntax error, unrecognized expression: <span class='brush-width-min'>1 px</span> <input type='range' min='1' max='50' step='1' value='undefined'> <span class='brush-width-max'>50 px</span> <span class='brush-width-val'>(5 px)</span>```
I've solved the problem by removing the newlines on the coffee code which contained html interpreted by jquery
It is a bit dirty, but it solves the problem, and I dont' know any other way on how to do that ...
And bonnus, I've updated the build scripts so they use uglify-js instead of uglify-js2, which is deprecated