pcl_visualization occur compile error on MSVC

[UnaNancyOwen]

The pcl_visualization occur compile error c2440 on msvc.

Error   C2440   'static_cast': cannot convert from 'double' to 'pcl::visualization::LookUpTableRepresentationProperties'    pcl_visualization   C:\pcl-1.8.0\visualization\src\pcl_visualizer.cpp   1495    
Error   C2440   'static_cast': cannot convert from 'double' to 'pcl::visualization::LookUpTableRepresentationProperties'    pcl_visualization   C:\pcl-1.8.0\visualization\src\pcl_visualizer.cpp   1741    

This error occurs because that can not directly cast to enum type from double type in msvc.
It must explicitly cast to int type from double type before cast to enum type.
(It seems to be implicitly cast to int type from double type in gcc. But, It seems not allowed in msvc.)

[SergioRAgostinho]

Fix got merged