weak is safer than unsafe_unretained
Fix for using https://github.com/nrbrook/TBXML.git rather than outdated TBXML repo.
Support for multiple consecutive LinearRings in a Polygon's innerBoundaryIs element

The form being:

<innerBoundaryIs>
  <LinearRing>
    <coordinates>...</cooordinates>
  </LinearRing>
  <LinearRing>
    <coordinates>...</coordinates>
  </LinearRing>
</innerBoundaryIs>
Updating to use designated initializers.

For compatibility with newer/forked versions of TBXML.
Merge branch 'master' of https://github.com/wooster/iOS-KML-Framework into wooster-master
Merge branch 'wooster-master'