Implement 'implicit new' feature #80

[horkhe]

Implements feature request #80. Implicitly created mock is:

• honest, an attempt to create an expectation for a module that is not available on a code path will fail. If a user does need one he can create it explicitly with non_strict option;
• passthrow, forwards functions that had no expectations created to the original module functions.

[eproxus]

Why is the link needed?

[horkhe]

I wanted implicit mock to have start_link semantic. But it is possible that start will fail due to undefined_module (when the respective module is not available on the code path), in that cases I wanted to throw error not_mocked, as it did before, to do that I started process without linking to survive possible process startup failure and converted undefined_module to not_mocked if it happened.

But may be it is better to just do start_link and fail with module_undefined if a user tries to create implicit mock of a module that is not available on the code path.

[eproxus]

I think it is better to keep the semantics from new rather than expect. Will update it.