(#ench) Improve documentation with jsDoc annotations

Added some more inline documentation to improve readability. 


Maybe some words about the terminology:


-Join point: These are called join points because they are points in a running program where additional behavior can be usefully joined. ('before', 'after', ....)

-Intercepting a method: This happens, when you apply the join points into a method.

-Advice: This is the additional code that you want to apply to your existing model. (the passed function)



From: http://en.wikipedia.org/wiki/Aspect-oriented_software_development