og_blueprints 5.x-1.0-alpha2

Changes since DRUPAL-5--1-0-ALPHA1:

• forgot to add the last crucial bit to the README.txt file.
• small changes to the text for the display layout settings editor buttons. also added t() to the $_POST['op'] value comparisons
• trying to resolve the problem in #253816; changed the unset return value of variable_get() in circumstances where no groups have been set. It's a band-aid, however, as this problem shouldn't be happening in the first place...
• updated comment - should be trying to use drupal_execute(), not drupal_process_form()
• nearly done with the group node type deletion handling
• built new system for handling group content types, in accordance with og-5.x-7.x and upwards. system has been debugged and, unlike the previous system, actually appears to work.
• forgot to add a potential namespace collision safety check. Also, relevant issue (in previous commit, and this one) is #249306.