Bug 896124 - Implement a JS_Init() JSAPI function, to be called before any other JSAPI operations (except JS_SetICUMemoryFunctions) are performed, to centralize whole-engine initialization tasks.  r=bsmedberg for the XPCOM bits, r=luke for the JS bits

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extra : rebase_source : fd308ab3bd76c67a0b128eaefae3edf177893fe1
Bug 890127 - Properly initialize and cleanup ICU, when enabled in JS engine builds.  r=njn

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extra : rebase_source : f1dd0e44afe1561e225bef1f31735caef1cea18c
Add #include <new> to mfbt/Vector.h so that placement-new actually works when that header hasn't been bootlegged.  No bug, r=too-long-spent-debugging-this

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extra : rebase_source : b4b3a5a10757d01d1c5957736210ed09e3c2b157
Bug 895792 - Fix RoundUpPow2's required precondition to not be wrong.  r=terrence

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extra : rebase_source : e42420628dad8b8e9fe37287fa8e08eb262fe615