[Paraview] Improvement in memory usage (no more leakage)

[Olumide]

A few moons ago, I wrote about what seemed to me to be memory leaks in 
Paraview -- that was back in the days of version 3.6.2.
See: http://markmail.org/message/julmjsirhzf3mosz

Fast forwad to today. I've loading datasets in Paraview all day and I'm 
pleased to observe that the memory issues I flagged have gone away. In 
the past I would have had to restart Paraview after a few data loads, 
but that's now a thing of the past, and I would like to thank the 
developers for a job well done.

- Olumide