[vmtk-users] New contributions

[Luca A. <luc...@or...>]

Many thanks to Martin Sandve Alnæs (https://github.com/martinal) and his fellow folks at Simula(http://simula.no/) for their recent contributions:

https://github.com/vmtk/vmtk/pull/71
https://github.com/vmtk/vmtk/pull/70
https://github.com/vmtk/vmtk/pull/69
https://github.com/vmtk/vmtk/pull/68
https://github.com/vmtk/vmtk/pull/67
https://github.com/vmtk/vmtk/pull/66 

Keep them coming!

Luca