Remove `X-Requested-With` info in XDR example

This is no longer necessary as using `xdr: native` will remove
all custom headers for you by default.
fix typo in docs
Merge branch 'dd-typo' of github.com:smikes/yui3 into smikes-dd-typo
Merge branch 'live-docs' into dev-master
[docs] Replace variants of Number
[docs] Replace variants of undefined
[docs] Replace variants of HTMLElement
[docs] Replace variants of Function
[docs] Replace variants of CustomEvent
[docs] Replace variants of EventFacade
[docs] Remove return types from chainable methods
[docs] Remove unnecessary 'Y.' from type docs
[docs] Replace HTML types with String
[docs] Rename XMLDoc to correct class name
[docs] Replace {Variant} with {Any}
[docs] RangeObject is Range in the DOM
[docs] Replace {config} with {Object}
[docs] Provide extra type information instead of {Array}
[docs] Fix typo in ModelSync.REST._onSyncIOStart
[docs] Remove extra + from ClassNameManager.getClassName