Changes

For many years, SpiderMonkey was written in C, and is gradually moving to C++. We still avoid many features such as run-time type information and exceptions, and generally avoid virtual functionsfor core data, but have come around to the glory of templates and namespaces relatively recently. Read the [[JavaScript:SpiderMonkey:C++ Coding Style|Coding Style]]. Do NOT read the portability guidelines, which I will not link to, since they are very out of date.