enhancement - improved data selection for source structures, now supports time and frequency selection and averaging, and averaging over source positions. Furthermore I extended the support for {pos}_ori_time structures. See http://bugzilla.fcdonders.nl/show_bug.cgi?id=2185


git-svn-id: svn+ssh://svn.fcdonders.nl/home/svnroot/fieldtrip/trunk@9353 0cf7c7f0-3615-4144-b4e6-68da3bce3cd0