enhancement - added optional weighting of headshape points in method headshape

git-svn-id: svn+ssh://svn.fcdonders.nl/home/svnroot/fieldtrip/trunk@7666 0cf7c7f0-3615-4144-b4e6-68da3bce3cd0
enhancement - implemented test script for http://bugzilla.fcdonders.nl/show_bug.cgi?id=2040
enhancement - implemented test script for http://bugzilla.fcdonders.nl/show_bug.cgi?id=2040
Merge branch 'master' of github.com:fieldtrip/fieldtrip