Iss #70: Provided the SignalMapper class that will act as a layer of abstraction between View components and Controller functions.
Iss #70: Updated default module level docstring
Iss #70: Updated module docstring
Iss #70: Updated BaseDialog docstrings
Iss #70: Provided AbstractLayout class that defines basic functionality for the layout that is added to the BaseDialog. This layout represents a wrapper for components, which will be containers for concrete widgets.