Contextual support for object method calls

A common use-case for functions is to call them in a particular context.  The current master branch applies all method calls in the global scope, which is problematic for OO applications.

Pseudo-code
```
If token.type == _t.PARENOPEN and prevToken.type == _t.VAR
    Assume method call, and bind to method's object scope, with a trailing comma
If token.type == _t.PARENCLOSE and previous token was a method call
    Strip trailing comma from output buffer
```

Additionally, I refactored the checkDot and buildDot methods, and borrowed them for this purpose.  Relevant test case added and passes.