Added privilege level start/end columns (#2328)

* Added privilege level start/end columns

Added 2 new columns to the users table to indicate when a users
privilege level date / time was recognised and when the privilege level
should end.

* Updated database header

Always forget about the database header file...

* Added priv level maintenance script

Added a bash maintenance script that can be run on a scheduled basis
that will demote privileged users that have the end times on the
accounts that are prior to the date/time the script is executed.

* Added donations table

Added donations table to db for tracking user donations

servatrice/migrations/servatrice_0019_to_0020.sql

@@ -0,0 +1,20 @@
+-- Servatrice db migration from version 19 to version 20
+
+alter table cockatrice_users add column privlevelStartDate datetime NOT NULL;
+alter table cockatrice_users add column privlevelEndDate datetime NOT NULL;
+update cockatrice_users set privlevelStartDate = NOW() where privlevel != 'NONE';
+update cockatrice_users set privlevelEndDate = DATE_ADD(NOW() , INTERVAL 30 DAY) where privlevel != 'NONE';
+
+CREATE TABLE IF NOT EXISTS `cockatrice_donations` (
+  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
+  `username` varchar(255) DEFAULT NULL,
+  `email` varchar(255) DEFAULT NULL,
+  `payment_pre_fee` double DEFAULT NULL,
+  `payment_post_fee` double DEFAULT NULL,
+  `term_length` int(11) DEFAULT NULL,
+  `date` varchar(255) DEFAULT NULL,
+  `pp_type` varchar(255) DEFAULT NULL,
+  PRIMARY KEY (`id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8;
+
+UPDATE cockatrice_schema_version SET version=20 WHERE version=19;