restructuring - made keepfields and removefields accessible as separate functions in utilities, see http://bugzilla.fcdonders.nl/show_bug.cgi?id=2596


git-svn-id: svn+ssh://svn.fcdonders.nl/home/svnroot/fieldtrip/trunk@9649 0cf7c7f0-3615-4144-b4e6-68da3bce3cd0
automatically synchronized identical files to revision 9649

git-svn-id: svn+ssh://svn.fcdonders.nl/home/svnroot/fieldtrip/trunk@9650 0cf7c7f0-3615-4144-b4e6-68da3bce3cd0