Move UI date formats into config properties

There are a number of different ways the UI displays date formats, depending on the page. For example:

• GuiDaemonJob extended results: yyyy-MM-dd HH:mm:ss z
• Grouper objects created/modified – groups, attr def, attr name: EE MMM d h:mm:ss aa zz yyyy
• stem created/modified (also a grouper object, but with its own formatting): yyyy/MM/dd HH:mm:ss.SSS (GrouperUiUtils.DATE_FORMAT)
• Group member show enabled/disabled date: yyyy/MM/dd HH:mm:ss
• Group member PIT start/end: yyyy/MM/dd kk:mm aa
• Audit entry date: yyyy/MM/dd kk:mm aa
• GrouperStatusServlet startup: yyyy/MM/dd kk:mm
• GrouperStatusServlet diagnostic error date: yyyy/MM/dd kk:mm:ss

Date formatting is a personal preference, and should be moved to a config where the defaults can be overridden.