[Cdash] coverage color palette

[Zack Galbreath]

You can view the results of this effort here:

http://trunk.cdash.org/index.php?project=Slicer4

Click on "Switch ... palette" to toggle between the two color modes.  
This link is just to the left of "Show Filters", towards the top of the 
page.

For now, if you'd like to use this new feature on your own CDash server, 
you need to update to SVN revision 3312 or later.  Once you do that, you 
can specify the default color scheme on your server by changing the 
value of $CDASH_CSS_FILE to either 'cdash.css' or 'colorblind.css'.  
When a user clicks on the "Switch palette" link it sets a cookie on 
their computer to remember their preference.