Update background section same as quick_tour.rst

Update text of ``background`` section same as ``sessions`` section of ``quick_tour.rst``
Merge pull request #1317 from omidraha/patch-1

Update background section same as quick_tour.rst
Typo found in second Declarative code block

There were two import statements for Configurator.
I removed the second import statement in the "__main__" since most of the
documentation declares all imports on the top of the source.

	modified:   configuration.rst