Adding a favicon for Girder.
Fixing style.
Merge pull request #196 from girder/adding-favicon

Adding favicon
Merge remote-tracking branch 'origin/master' into item-delete-ui

* origin/master:
  Fixing style.
  Adding a favicon for Girder.
Moving filtering to the model layer and fixing pathToRoot.

The path-to-root functions in the item and folder models now return
a list of objects that indicate the type and then the full document for
the parent object.