CommonJS + global compatibility

[jonbri]

Detect if in an environment like NodeJS where ticker-log will be used as an NPM module, or loaded like jQuery often is where it just exposes a global variable.

Something like this: https://github.com/jquery/jquery/blob/master/src/wrapper.js

also see: http://sinonjs.org/releases/sinon-1.17.3.js for an example