[CSS] Remove completion restrictions

[deathaxe]

Suggest properties also within meta.selector as this is the most likely scope in front of nested selectors, if a property is not yet terminated by semi-colon.

As completions are much more likely, do no longer suppress word completions.

Without this commit auto-completion no longer provides property-name completions in front of nested selectors.

Example:

div {
  color: red;
  bo|  <- no more completions here

  h2 {
    text-decoration: none;
  }
}

reported at https://github.com/SublimeText/Sass/issues/107