Create a more minimal CSS file for SWT (for Windows)

There were a lot of things in the SWT CSS file that were no needed, and
some that were wrong. This one has been tested on Windows. Here is what
it contains:

- A 4px padding for composites
- A 6px (top and bottom) padding for ToolBars. This is so the toolbar is    
  at least 12px high. If it's not, toolbar items won't render on 
  windows.
- 9px height for TableColumns, which actually gets translated into 
  TableHeader Height in RAP.
- No padding or spacing for all other widgets 
  (RAP appears to put some in).
  

Change-Id: I1f1df72eba0daf2e9e6d43630157e426b5b0ab95