Git commits in Moodle 2.8.8 by Michael Aherne

commit 4750b1379f8f0d44be4f07dc0c79542fdafe5961
Author: Michael Aherne <michael.aherne@strath.ac.uk>
Date:   Mon, 24 Aug 2015 16:06:26 +0800
Tag:    v2.8.8

MDL-51181 config: Correct documentation of lock_factory

commit 53eaea59440d7f45b73f55fb9678cafbdedad6a3
Author: Michael Aherne <michael.aherne@strath.ac.uk>
Date:   Thu, 06 Aug 2015 19:53:17 +0800
Tag:    v2.8.8

MDL-51016 messaging: Fix email attachments on Windows

commit 772dc9df94a097288a7bdcf67186367ce5fc4b47
Author: Michael Aherne <michael.aherne@strath.ac.uk>
Date:   Fri, 26 Jun 2015 22:35:33 +0800
Tag:    v2.8.8

MDL-50466 tasks: Specific minute values for log cleanup

commit a02fc8bb051d9f66a3966c478117e5fe48e098a1
Author: Michael Aherne <michael.aherne@strath.ac.uk>
Date:   Tue, 28 Apr 2015 16:14:31 +0800
Tag:    v2.8.8

MDL-50490 cron: Prevent tasks from leaving uncommitted transactions