Add 'collapse all' and 'link with main panel' buttons to navigation

Signed-off-by: Madhura Jayaratne <madhura.cj@gmail.com>
Change icon with sprites

Signed-off-by: Madhura Jayaratne <madhura.cj@gmail.com>
Merge pull request #1104 from madhuracj/nav

Add 'collapse all' and 'link with main panel' buttons to navigation