Revert "Made list items clickable again"

This reverts commit cf1a5c1668c7a4508d5ed7fbde3ea9a33222b951.
Revert "Using CellTable for the list, sortable now"

This reverts commit 899e170ccfec03d3b6f10ca5d58330a454996113.
Updated list UI based on VerticalPanel, added Spinner, refactorings...
Added simplistic DirZip servlet
Some minor tweaks
small UI tweaks