Fixes #657

[joeytakeda]

Adds another rule to odd.css to ensure colon and space

[ebeshero]

@sydb @martinascholger @HelenaSabel I think we just lost track of this work that @joeytakeda did in May to improve the output CSS of generated ODDs. I just updated the branch and the tests are passing. (I'm not suggesting we merge it for the imminent release, but we may want to continue working on CSS for custom ODD-generated HTML on this branch, and merge for the next release?)

[HelenaSabel]

@ebeshero: I will be partial to merging the current work as it is after the release (if @joeytakeda agrees). In principle, the current generation of ODD documentation will be superseded relatively soon so I wonder if it isn’t better to work on issues with higher priority.

[sydb]

I did not investigate why, but with this PR there is not just a “: ” after the classname before the list of attributes, there is a “ : ”. (That is, space-colon-space instead of just colon-space.)