Fix "selectedOptions" binding bug

Fixes an error where the binding does not update non-observable property
values.
Make css binding accept any class name (matches 2.1.0 behavior).
Merge pull request #704 from SteveSanderson/704-expand-css-class-names

css binding doesn't work with class names with slashes, etc. in 2.2
Merge pull request #743 from angelyordanov/master

SelectedOptions binding not updating non-observable properties