Merge pull request #2 from joeegan/master

Syntax corrections and the ability to use without instantiation
Update observer.js
Move event bubbling to builder function
allow lazy instantiation of Observer

- initialise topics via private getter to prevent being undefined
- protect against invalid use of subscribe (no handler supplied)
Move build to grunt

- add grunt task to uglify observer js and put in target folder
- .gitignore added to ignore node modules etc
remove TODO from readme

- any info can be added to the github page
Merge branch 'master' of https://github.com/jimenglish81/observer