Fix h4 heading which used to be p

However this h4 margin look poor so its design needs
improvement
Constructor instead of Singleton

We haven't seen Singleton yet. However this statement looks quite
strange as a whole. Isn't Module true encapsulation?
IndexOf actually implemented LastIndexOf

I also don't understand why method start here with awful
capital letters.
Simplify implementation of ObserverList.Insert/RemoveAt

Splice can do for all those cases. If it's considered performance
optimisation here I suppose that readability should come first.
Fix capitalization problems is ObserverList
Fix coding style, remove unused code

* fixed capitalization
* fix overall coding style (why new Function?, why ["onclick"]?)
* remove unused code from ObserverList so it's easier to read and
understand
mailCounter displayed before being incremented
Fix checking for undefined variable

* also small spacing improvements
Add missing ) in function call
Fix flickr getJSON example

* plus trailing spaces fixed
Merge pull request #116 from neojski/small-fixes1

Small fixes1