Added TabsPanel widget
Fixed bug
Added the panel that will contain the options of action of the elements
Added new contructor method in TabsPanel widget and remove MoreElementComponent class
Introduced the panel where the conditions of an element for be visible are decided
Added i18n
Now the user can enter the name of the flag
Added FlagButton class for show a flag
Minor changes
Now the FlagPanel show the flags in a GridPanel
Javadocs and formatting.
Improved UI widgets.
Improved Gallery and ElementGallery delete functionality.
Minor changes
Merge pull request #256 from RotaruDan/TabPanel2

Added a TabsPanel