cmake VXL examples

Kitware/kwiver CMake/kwiver-depends-VXL.cmake :9 

find_package( VXL REQUIRED )

InsightSoftwareConsortium/ITK Modules/ThirdParty/VNL/CMakeLists.txt :8 

find_package(VXL 3.0.0 REQUIRED)

vxl/vxl config/cmake/Modules/UseVXL.cmake :56 

find_package(VXL)