Added *features* parameter: needs help.

*features* exists as a way to detect capabilities of a Common Lisp
 system.

This patch should/mostly implement \*features\*. Unfortunately, I have an issue:

```
CL-USER> *features*
(#<javascript object> #<javascript object> #<javascript object>)
```

Of course, if I define \*features\* on the REPL it works.

I'm not sure how to ensure that I'm creating correct Lisp objects in the compilation process rather than Javascript objects. Please advise and I will finish up the pull request.