Merge central and inbound

content/base/public/Makefile.in

content/base/public/nsContentUtils.h

content/base/public/nsIMutationObserver2.h

content/base/src/nsContentUtils.cpp

content/base/src/nsDOMAttribute.cpp

content/base/src/nsDOMAttribute.h

content/base/src/nsDOMMutationObserver.cpp

content/base/src/nsDocument.cpp

content/base/src/nsNodeIterator.cpp

content/base/src/nsNodeIterator.h

content/base/src/nsNodeUtils.cpp

content/base/src/nsNodeUtils.h

content/base/src/nsStubMutationObserver.cpp

content/base/src/nsStubMutationObserver.h

content/base/src/nsTextNode.cpp

content/base/src/nsTextNode.h

content/base/src/nsTreeWalker.cpp

content/base/test/Makefile.in

content/base/test/test_bug590771.html

content/base/test/test_bug598877.html