readme: update with billjojo's changes

git-svn-id: https://plugins.svn.wordpress.org/shibboleth/trunk@889048 b8457f37-d9ea-0310-8a92-e5e31aec5664
Update with specific details regarding the new option and the use of required sessions.

git-svn-id: https://plugins.svn.wordpress.org/shibboleth/trunk@889049 b8457f37-d9ea-0310-8a92-e5e31aec5664
Remove unneeded check. This was fixed in WP 3.3.0 and now just leads to error messages in the Apache log due to the value of $wpdb->sitemeta
Errors are similar to:

[Thu Apr 03 21:03:06 2014] [error] [client XX.XX.XX.XX] WordPress database error You have an error in your SQL syntax; check the
manual that corresponds to your MySQL server version for the right syntax to use near
'WHERE meta_key = 'shibboleth_logout_url' AND site_id = 0' at line 1 for query SELECT meta_value FROM  WHERE meta_key = 'shibboleth_logout_url' AND site_id = 0 made by activate_plugin, do_action('activate_shibboleth/shibboleth.php'),
call_user_func_array, shibboleth_activate_plugin, shibboleth_add_option,
referer: http://wpdev.hvcc.edu/wordpress/wp-admin/plugins.php?deactivate=true&plugin_status=all&paged=1&s=

Note the blank space between FROM and WHERE.

git-svn-id: https://plugins.svn.wordpress.org/shibboleth/trunk@889050 b8457f37-d9ea-0310-8a92-e5e31aec5664
readme: update version notes; bump required WP version to 3.3

git-svn-id: https://plugins.svn.wordpress.org/shibboleth/trunk@889051 b8457f37-d9ea-0310-8a92-e5e31aec5664
readme: typo fix; add github info

git-svn-id: https://plugins.svn.wordpress.org/shibboleth/trunk@889052 b8457f37-d9ea-0310-8a92-e5e31aec5664
rm screenshots from plugin repo

git-svn-id: https://plugins.svn.wordpress.org/shibboleth/trunk@889053 b8457f37-d9ea-0310-8a92-e5e31aec5664