Experimental: add Ctrl[+Shift]+W hotkey to inspect "window" object
Inspect "window" object: correctly ensure tree loaded
(needed for not yet loaded web pages)
Fix "anonymous function does not always return a value" warning
Inspect "window" object: fixes for Firefox 2.0
Inspect "window" object: do nothing, if there is no "context" node
Inspect "window" object: use beginUpdateBatch()/endUpdateBatch() to slightly improve performance
Merge branch 'origin/test/attrs_inspector/inspect_window'