Bug 831428 - Make ContentChild's nsIConsoleService implementation have thread-safe addref/release methods, and add a comment to nsIConsoleService indicating that this is necessary. r=bsmedberg, a=lsblakk

This patch is only for b2g18; we're going to do a different fix for trunk.  See this bug.
Bug 819000 - Preload some JSMs and XPCOM services into the preallocated process to speed up app startup. r=cjones, a=akeybl