Add simple initialization based configuration support and the ability to configure if the sign in is stored in the session

This PR includes a feature that @gonzalo-bulnes  has identified in issue #19 (and could possibly help with #20 and #12).

1. Initial configuration framework to support an initializer based configuration file
2. A single configuration to define if the token authentication should be stored in the session (i.e. can the user navigate to other pages as an authenticated user after a single token authentication).

I have included updates to the documentation however no test cases :(

@gonzalo-bulnes please let me know if it helps if I break these up more cleanly between issues #19 and #20.  Thanks!