Bug 796925 - Fix clang-on-Linux bustage in parser/html/jArray.h.  rs=hsivonen, a=overholt

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extra : rebase_source : 1efb96732f06fea908dfa5b3a711bc1eafe99132
Bug 831279 - Part 1: Backout changeset 9adf5ca922a4 (bug 798354) because it relied on the assumption that C++98 is a sane language and allows sizeof(class::member), but that sanity has just been added to C++11, a=overholt
Bug 831279 - Part 2: Port hg cset 978e9865042: Eliminate a few nullptr-to-bool conversions to avoid a clang warning (which we upgrade to error) in some clang revs.  No bug, r=sparky, a=overholt

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extra : rebase_source : 6b45c8e1dd07449a5ebc34704c19e05fe155f628
Bug 830125 - Add the preferences memory reporter off a runnable, so as to avoid recursive GetService calls. r=njn, a=overholt
Bug 809949 - Dump memory reports when 'memory report' is written to a special fifo on disk. r=glandium, r=njn, a=sicking