[#20288] Update the CodeRay Ruby syntax highlight example.

[#20288] Update the CodeRay Ruby syntax highlight example.

This commit changes the following:

* Remove line numbering from syntax highlight example.
* Add span with 'CodeRay' class around the syntax highlight example.
* Fix span classes in the syntax highlight example:
** Ruby scanner changed from ':reserved' to ':keyword' with CodeRay 1.0.0.
* Remove obsolete line numbering styles.
* Fix internal stylesheet to match CodeRay 1.1.0 (preserving r10132's changes).
* Sort internal styles and remove superfluous newlines between styles.

Contributed by Mischa The Evil.

git-svn-id: http://svn.redmine.org/redmine/trunk@14492 e93f8b46-1217-0410-a6f0-8f06a7374b81