Add stubbed PDDOMDomainController class for view
hierarchy debugging.
Swizzle UIView add/remove/exchange methods to
monitor changes in the view hierarchy.
Add simple way to generate nodeIds for views and
a dual dictionary setup to allow quick lookup of
views to nodeIds in both directions.
WiP: auto connect to ponyd service published via bonjour

Simple proof of concept.
Implement PDDOMCommandDelegate's getDocument…
method. Returns the root document node and a
root element with no children.
Enable view hierarchy debugging in PDTwitterTest
Traverse the view hierarchy and generate a very
basic node for each view.
Show attributes for objects based on the
visibleAttributesKeyPaths array set in init.
Fix bug with overwriting the nodeIds for views
Implement node highlighting
Fix bug in shouldIgnoreView
Update the elements panel as views are added and
removed from the view hierarchy.
Improve stopTrackingView to stop tracking its
subviews too, and remove the highlight view if
necessary.
Don't show the highlight overlay in the hierarchy
Properly hide the highlight overlay.
Respond to window changes in a not-so-elegant way
Use KVO to monitor changes in view attributes to
keep the information in the elements panel fresh.
Implements node removal
Support editing of attributes that map to KVC
key paths. Query the runtime to infer the type of
the attribute and parse the string accordingly.
Support BOOL attributes with more readable YES/NO