ENH: [Mayavi] Replace the execfile for custom views with an import,  	    with caching, for speed.
ENH: [Mayavi] Replace the execfile for custom views with an import, 
	    with caching, for speed.



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