…s in parents with .blockMsgClass

jQuery UI Datepicker creates its calendar at the end of the document (mostly
outside an active modal jqm dialog) which disallows to change the year (select)
in a modal jqm. The solution was found in
<http://stackoverflow.com/a/18188375/2627857>
and adopted for jqModal.

This allows two solutions:
1. add `blockMsg` css class to the datepicker div
2. or set the (new) jqm option `blockMsgClass` to '`ui-datepicker`'

Both settings allow the focus event for the year select to bypass the "Focus Examination Function".