Add back SmokeMethodDescr to handle static/instance methods.

C++ can have same named static as well as instance methods which
must be handled in pysmoke resulting in the need for the method
descriptors.
Also removed the `is_static_method` method of ClassDef, since
the name is insufficient to determine whether the method would
be static or not.
Run tests with `unittest discover`

Nosetests messes up with transplant_class causing issues with
metaclass, since transplanted classes are created with 'C' name
instead of the actual name which is used by the SmokeMetaClass
to find native class to bind to.
Merge pull request #2 from pankajp/add-mmethod-descr

Add back SmokeMethodDescr to handle static/instance methods.