Fix for Issue #106

This line was missed when upgrading NumArgs - sorry about that!
Merge branch 'master' of github.com:justinethier/husk-scheme
Added another bugfix to the 3.9 section
Added a safety check and TODO
Work around for issue #95

Another issue with load is that it does not handle the case when code is passed as the filename. This is exactly the scenario for require-extension. For now we can work around it by calling `evalLisp` to evaluate the code at compile time. For basic use cases this works well enough. The changes need to be generalized and extended to the other versions of `load`.
Bumping to 3.9
Revised the 3.9 section
Removed dead comments
Consolidated the `load` code
Added a stub for `%import`, use r5rsEnv
Revised 3.9 section
Minor revision
Added TODO stub for `let-syntax`
Use a bodyEnv to compile lambda body

First step towards a smarter compiler
Removed unused parameter
Issue #107 - Compile time variable tracking

Keep track of variables at compile time by storing variables introduced by `define` and `lambda` statements. Then validate that variables are defined when dereferencing them.
Use r5rs environment instead of primitiveBindings
Added a 3.10 section
Refactoring

- Use a single run-time function to look up variables, to reduce the amount of generated code.
- Added header comments to some functions at the start of the file, since there is a lack of documentation in this module.
Initial file