Implement test cases

[jbaron]

Start creating test cases for the current and new functionality. Still many things to be decided:

1. Using functional, unit or behaviour type of approach
2. What framework to use (QUnit, Jasmine, Cucumber, ..)
3. How to test, in browser or other possibilities (like in node)
4. How much test coverage is final goal

This should improve overall quality of application. Now sometimes bugs are introduced because of lack of automated test coverage,