Updated cgal finder

cmake/CGAL_GeneratorSpecificSettings.cmake

@@ -8,12 +8,21 @@ if ( NOT CGAL_GENERATOR_SPECIFIC_SETTINGS_FILE_INCLUDED )
     set(CGAL_AUTO_LINK_ENABLED TRUE)
   endif()
 
-  if (MSVC12)
+  if     ( MSVC15 )
+    set(CGAL_TOOLSET "vc150")
+    message( STATUS "Using VC15 compiler." )
+  elseif ( MSVC14 )
+    set(CGAL_TOOLSET "vc140")
+    message( STATUS "Using VC14 compiler." )
+  elseif ( MSVC12 )
     set(CGAL_TOOLSET "vc120")
+    message( STATUS "Using VC12 compiler." )
   elseif ( MSVC11 )
     set(CGAL_TOOLSET "vc110")
+    message( STATUS "Using VC11 compiler." )
   elseif ( MSVC10 )
     set(CGAL_TOOLSET "vc100")
+    message( STATUS "Using VC10 compiler." )
   elseif ( MSVC90 )
     set(CGAL_TOOLSET "vc90")
     message( STATUS "Using VC90 compiler." )