Make getting conf variables more friendly

This creates a .conf attribute through which configuration variables can be accessed easily. Now, instead of doing this:
url = self.conf_get('main', 'ur')
A client can do this:
url = self.conf.main.url

The conf_get(...) function remains available and unchanged. If you want to cast to an int or float, you will still have to do self.conf_getInt(...), etc.  This changeset does not affect those functions either.