Support NSToolbar and Document Windows

These changes support:

 * NSToolbar (with a standard-height title-bar) — toolbar heights are empirically derived for various modes; there appears to be no API for this info;
 * Document windows — the calculations for positioning the various title-bar elements were incorrect for versioned documents; in particular, the Versions standard window button (and associated dash) should only affect the title's width, not it's x-position.