Stop unconditionally setting the z-index on sync

This causes a bug where hidden widgets set the z-index of the mask
to their own z-index. The mask z-index is anyway correctly set
previously in _uiSetHostVisibleModal.
Upgrade Handlebars.js to v1.0.11
Adding ignores to Editor unit test gh issue #653
Merge branch 'handlebars-v1.0.11' into dev-master
Build Handlebars @ v1.0.11
Tree: Make node destruction a little less destructive.

Instead of setting various node properties to `null` when destroying a node,
set them to empty values. This makes it a little easier to figure out what
went wrong when you accidentally try to use a node after destroying it.
Tree: Better handling of destroyed nodes in createNode(), insertNode(), and traverseNode()

These methods will now throw (or log) informative error messages instead of
failing cryptically (or succeeding when they shouldn't) if you try to use them
with destroyed nodes.
Update Tree history.
Tree: Add tests to cover the case where an errorFn handles destroyed node errors.
Use counter to prevent multiple resume() fires.
Compare form query with getElementsByTagName results rather than count to accomodate injected form(s).
replace areSame => areEqual because older browsers return a string, as opposed to a number
Merge branch 'modal_zindex_reset_by_hidden_widget_fix' into dev-master
build widget-modality
Build tree.
Remove unnecessary <code> tag

Fixes problem on YUIDoc
Build anim. Doc changes only.
Merge branch 'live-docs' into dev-master
Merge branch 'dev-master' into dev-3.x
Merge branch 'live-docs' of github.com:yui/yui3 into live-docs