Make the List View appearance match the mockups.

Make the List View appearance match the mockups.

It doesn't match exactly but it's much better than it was.

* mockups/listview-contacts.html: Remove unused css classes.
* mockups/listview-projects.html: Remove unused css classes.
* src/main/java/org/glom/web/client/ui/ListViewImpl.java: Display 15
rows instead of 20. Rename vPanel to mainPanel. Use FlowPanel (div)
for mainPanel instead of VerticalPanel (table). Set style name on
CellTable. Set style name on Details column. Right-align Details
buttons.
* src/main/webapp/style.css: Adjust properties to match the mockups.