Adds Docstrings for Functions and Classes

This just adds some basic docstrings to explain functionality.
Adds Merge Method

This commit adds a new comparison method to the base object that allows
the user to perform a match and pull over data from another object. The
results are stored on the object that serves as the basis for
comparison, just as in the match method.
Modifications to Write Method

This changes the write method (which I never bothered to get working as
it should) so that the user can no longer specify args that represent
fields that are to be written to the output csv file. That functionality
should be added in later, but for now, the method is simplified and
works as it should.