Merge branch '2.0-core' of https://github.com/rwldrn/jquery

Merge branch '2.0-core' of https://github.com/rwldrn/jquery

* '2.0-core' of https://github.com/rwldrn/jquery:
  Explanations for each step of isPlainObject
  obj === Object(obj) comparison is an unnecessary artifact from refactoring
  Ensure that null/undefined args don't choke on native indexOf
  Further reduction, thanks @dcherman
  Straightforward support note
  Straightforward support note
  Remove setTimeout for body existance
  2.0: Reduce globalEval
  2.0: Reduced parseXML
  2.0: Reduce isPlainObject
  2.0: Remove isArray shim
  2.0: Remove now shim
  2.0: Remove inArray shim
  2.0: Remove JSON.parse shim
  2.0: Remove trim shim
  2.0: Removes attachEvent paths for jQuery.ready()