SldService community module tweaks

Change XML output from:
&lt;CssParameter&gt;&lt;@name="fill"&gt;&lt;#text="#000000"&gt;&lt;/CssParameter&gt;

to:
&lt;CssParameter name="fill"&gt;#000000&lt;/CssParameter&gt;

Also:
- Get rid of initial black color on ramps
- Add gray, jet ramps to available options in ClassifierResource