Make dependency on NodeJS optional

[palantir]

Make dependency on NodeJS optional

[derekcicerone-zz]

The performance of Rhino is terrible. dynjs requires Java 7 but this project uses Java 6 (people complained about the Java 7 requirement). If you follow the TypeScript discussion boards, they are even having trouble supporting multiple JavaScript engines due to slight variations between the behavior in each. I don't think supporting multiple JavaScript engines (since some people want to keep using Java 6) is a good idea at this time. The Node.js installation isn't that onerous, is it?

[derekcicerone-zz]

After looking at dynjs there are 2 other concerns: 1. the maturity of that project (and its future) 2. it doesn't have the support for the nodejs libraries, so that would need to be added on top. In theory its available via http://nodyn.io/ but thats 2 new projects chained together that I don't necessarily trust and that's just too much risk. I think we should stick with nodejs for now. It's well-supported by TypeScript and not very difficult to install.