Remove more reliance on the configure.hpp header

  As it stands, I just don't see the need for the configure header at
  this point. While I did add a new type named 'build' to check if RTTI
  is disabled or not, the header will only be used by one or two files,
  rather than all of them.

  I may go *back* to using the configure.hpp header, as it did bring a
  few types into the v1 namespace that are used in multiple areas.

  The classes where the std types and what not are typedef'd exist as
  private typedefs.

Modify safe type to build properly under all MinGW distributions.

  This was handled by removing the reliance on the `std::future<T>`
  type. This closes #11.

Modify the safe type unit tests to follow the new interface.

  I am most likely going to have all the exception and error handling
  occur within the test runner, rather than being wrapped by the test
  class's submission function [operator =], and handled by a future.

  If anything the std::future<T> type not existing under some MinGW
  distributions will be a great case for an API change in v2 down the
  line.