Parse Selectors: don't add '*' to list of pseudo elements
Compile Properties / Values: two bugfixes

- change return value for a tag which can be added to the 'to_set' array to
  False (as None is a valid value)
- extra handling for value None, produced slightly incorrect value for
  'tag_value' tags: current.tags->null
  this evaluates to null, but is quite redundant