Author: Petr Skoda
MDL-29029 add new "Admin tool" plugin type
http://git.moodle.org/gw?p=moodle.git;a=commit;h=11b24ce7b22909b0ee27abc02261a66c94a18ec2
http://github.com/moodle/moodle/commit/11b24ce7b22909b0ee27abc02261a66c94a18ec2
+ 2.2 en [type_tool,core_plugin]
+ 2.2 en [type_tool_plural,core_plugin]