CMake fix: OpenEXR and Tiff are linking dependencies of OIIO, and fix for Boost-Cycles-OIIO order

The NOT BOOST test was changing Cycles so should be before the
cycles-oiio link (by Campbell Barton, thanks)

And exr and tiff are required for oiio (on OSX at least)

CMakeLists.txt

@@ -408,11 +408,6 @@ if(WITH_PYTHON_MODULE)
 	set(WITH_HEADLESS ON)
 endif()
 
-# auto enable openimageio for cycles
-if(WITH_CYCLES)
-	set(WITH_OPENIMAGEIO ON)
-endif()
-
 # enable boost for cycles, booleans, audaspace or i18n
 # otherwise if the user disabled
 if(NOT WITH_BOOST)
@@ -431,6 +426,17 @@ else()
 	set(WITH_BOOST OFF)
 endif()
 
+# auto enable openimageio for cycles
+if(WITH_CYCLES)
+	set(WITH_OPENIMAGEIO ON)
+endif()
+
+# auto enable openimageio linking dependencies
+if(WITH_OPENIMAGEIO)
+	set(WITH_IMAGE_OPENEXR ON)
+	set(WITH_IMAGE_TIFF ON)
+endif()
+
 # auto enable llvm for cycles_osl
 if(WITH_CYCLES_OSL)
 	set(WITH_LLVM ON CACHE BOOL "ON" FORCE)