Fixes comparisons between nil metatables
Adds support for process.version
Merge #436 r=@kevinmehall: Adds support for process.version

@kevinmehall r?
Adds test for nil and table comparisons.
Merge #434 r=@johnnyman727: Fixes comparisons between nil metatables
Adds test case for #289
Adds better tests for #289
Adds support for primitive boxing. Fixes #289
Using metatables to preserve primitive state from mutation
Adds primitive boxing for Object function