GPII-738: Fixing problems in headings.

http://issues.gpii.net/browse/GPII-738
@jobara <section> is used when someone wants to construct a document outline. It is mainly used with pages containing text.  
http://html5doctor.com/avoiding-common-html5-mistakes/ 
http://www.w3.org/TR/2008/NOTE-WCAG20-TECHS-20081211/H42

We used <h1>,...,<h4> in order to provide headings to blind users that want to navigate through them (Press "Insrt"+"F7" for NVDA to see/hear the headings or Press button "H").