grips-css: function to normalize selectors

Whenever selectors are processed by the codegen, and they are base64 encoded for the grips partial id's, these selectors need to be normalized. Whenever render(..) is called with a selector, that selector should be normalized, so it can match when base64 encoded the proper grips partial.

Examples of necessary normalizations:

foo     bar

-> foo bar

foo     >       bar

-> foo > bar

foo    /* something */    bar

-> foo bar