Fixing removal of $ from config values

This fixes the remove of dollar signs in config values (for example passwords). Before the install would fail if your password had a $ in it because what was returned did not match what was passed in (Example: If your password is Pa$sw0rd it would write Pasw0rd to the config, thus triggering the error on line 52.
Fixing error when dates are not provided.

When dates are not provided this was throwing an error (because DateTime::createFromFormat returns false if the date supplied is not valid). This change will just null out any dates that aren't provided.
Merge pull request #37 from csouth/master

Fixing removal of $ from config values