Bug 973476 - Remove old, weird, unused SHELL_HACK code from shell/js.cpp. r=jorendorff

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extra : rebase_source : 871c11bc73baeff8050170efab97c1c491562a84
Bug 976369 - Increase Yarr's match limit to unregress dzone website. r=jandem

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extra : rebase_source : b7441e399e223b48710ce82e6c65776610c16da4