hotfix: add `romo-user-select-none` style class
hotfix: add `romo-user-select-none` style class

Use this to prevent user selection on any element.  This is a
convenience style class similar to all the other style classes.

This applies the following styles:

```css
  -webkit-user-select: $value;
     -moz-user-select: $value;
      -ms-user-select: $value;
          user-select: $value;
```

/cc @jcredding

redding/romo,redding/romo,redding/romo