Add support for Anything and Etc objects on assertCalledWith.
Add assert.ok to assertCalledWith to be sure function was called.

Without this, the error sounds too cryptic: Cannot read property 'length'
of undefined.
Update README with Anything / Etc.
Change useless assert.ok call to assert.
Assert that SuperMock.Etc is not misplaced.
Merge pull request #2 from n2liquid/anything-etc-feature

Anything / Etc feature for assertCalledWith