ViSP 3.0.1 release

This ViSP 3.0.1 release includes a lot of improvements and bug fixes.
Big thanks to everyone who participated!

The changes are summerized in https://github.com/lagadic/visp/blob/master/ChangeLog

Contributors:

$ git shortlog --no-merges -ns 3.0.0..3.0.1
   326  Fabien Spindler
    79  fspindle
    59  Souriya Trinh
    13  s-trinh
     5  marc pouliquen
     4  Nicolo Pedemonte
     3  Fabien.Spindler
     3  ayol
     2  Souriya TRINH
     2  Jason Chevrie
     2  Aurelien Yol
     2  benoitheintz
     1  Vincent Drevelle
     1  Pierre-Marie Kerzerho
     1  Continuous integration
     1  Marc Pouliquen
     1  Karamaz0V1
     1  TheMrNomis