Style enhancements to Board Headers

- Removed space between Board Headers and Board content
- Header titles are now left justified and board header stats right justified
Added styles to collapse the quick navigation area of the page.
Board Widget support for fixed height Columns

- Updated jquery.SPControlBoard.js to support new input params (height) and new method (setHeight).  Change to actually make the board have fixed height was done in setBoardColumnHeight().
- Updated SPWidgets.SPControlBoard.md documentation to include new input param and new available method.
- Board Demo updated to use the new Height option.
Updated Demo showcase and built library files to the latest code.