Remove now useless configuration data.

Once configuration data has been injected into the various classes it is
no longer necessary in Configure. Keeping it in configure only consumes
more memory and give the impression that changing data in configure will
update the other classes.

App/Config/bootstrap.php

@@ -113,6 +113,15 @@
 Email::config(Configure::read('Email'));
 Log::config(Configure::read('Log'));
 
+// Remove configuration data from Configure.
+// We don't want to give the impression that this data is mutable.
+Configure::delete('Cache');
+Configure::delete('Datasources');
+Configure::delete('EmailTransport');
+Configure::delete('Email');
+Configure::delete('Error');
+Configure::delete('Log');
+
 /**
  * Custom Inflector rules, can be set to correctly pluralize or singularize table, model, controller names or whatever other
  * string is passed to the inflection functions