Added strings and numbers to the grammar.

Will complie, but the repl doesn't like it.
Repl accepts objects with strings or numbers as keys.
Cleaned up.
Minor grammar.
Tests for objects.
Type test for objects with string/number keys.
Standardized object string key type representation.
Conditional object wrapping to clean up raw js output.
Fixed string output of object keys.
Merge pull request #166 from joneshf/issue-28

Issue 28