VS2017 cmake support

CMakeLists.txt

@@ -184,7 +184,7 @@ if (OX_HAVE_LIBPNG)
 		set(LIBPNG ${libprefix}png)
 
 		if (MSVC)		
-			if (MSVC_VERSION EQUAL "1900")
+			if (MSVC_VERSION GREATER_EQUAL 1900)
 				set(LIBPNG ${LIBPNG}-2015)
 			endif()
 		endif()		
@@ -202,7 +202,7 @@ if (OX_HAVE_LIBJPEG)
 	set(LIBJPEG ${libprefix}jpeg)
 	
 	if (MSVC)
-		if (MSVC_VERSION EQUAL "1900")
+		if (MSVC_VERSION GREATER_EQUAL 1900)
 			set(LIBJPEG ${LIBJPEG}-2015)
 		endif()	
 	endif()