CMS-3476 Replace ExtJS grid - Try letting ContentGridPanel2 use ContentSummaryViewer to display the name column

Replaced basic NamesAndIconView with ContentSummaryViewer element.
Major update of the display style:
Updated columns width, colors, text align.
Updated Grid code, so it will react on Responsive UI events.
Fixed several firefox bugs, considering grid.
Merge pull request #765 from enonic/CMS-3476

CMS-3476 Replace ExtJS grid - Try letting ContentGridPanel2 use ContentS...