Removed tabs, and turned them into buttons.  Reorganized layout, and fixed items that should have had enabled_when on.
Removed tabs, and turned them into buttons.  Reorganized layout, and fixed items that should have had enabled_when on.

dmsurti/mayavi,alexandreleroux/mayavi,alexandreleroux/mayavi,dmsurti/mayavi,liulion/mayavi,liulion/mayavi