Back out a5a1dd3bd8ae (bug 860029) for stupidorange
Bug 856368 - Remove DEBUG_TRACEMALLOC_PRESARENA.  r=roc
Bug 856368 - Merge nsPresArena::mState into nsPresArena itself.  r=roc
Bug 856368 - Adjust memory reporter SizeOf methods accordingly.  r=roc
Bug 856368 - Inline the AllocateBy* and FreeBy* methods into the header.  r=roc
Bug 856368 - Convert some comments into proper doc-comments.  r=roc