Disable failing reftest (#3636)
auto merge of #3637 : mbrubeck/servo/disable-link-style-reftest, r=pcwalton
Move windowing code out of the compositor

This is mainly just moving code around, in preparation for further changes to
the "windowing" API.
Factors out DOM traversal, keeping the code in `parallel` free of traversal-specific logic.

DOM traversals and Flow traversals look very similar. This patch unifies them
with the preorder/postorder pattern. Hopefully, it also opens the door for writing
the traversal code only once, instead of the duplication we have today.
Merge pull request #3563 from mbrubeck/app2

Move windowing code out of compositor, take 2. r=larsberg
Update web-platform-tests.
Merge pull request #3638 from cgaebel/parallel-dom-traversal

Factors out DOM traversal, keeping the code in `parallel` free of traversal-specific logic.
auto merge of #3641 : Ms2ger/servo/wpt_20141010, r=Manishearth
Use Gecko's simpler Bloom filter instead of one based on hash
stretching.

This preserves the usage of the Bloom filter throughout style recalc,
but the implementation is rewritten. Provides a 15% improvement on
Guardians of the Galaxy.