bugfix - better handling of variance and degrees of freedom, see http://bugzilla.fcdonders.nl/show_bug.cgi?id=2061#c5. Thanks to Joscha.


git-svn-id: svn+ssh://svn.fcdonders.nl/home/svnroot/fieldtrip/trunk@10051 0cf7c7f0-3615-4144-b4e6-68da3bce3cd0