cmake: find openexr release/debug separately and define them as such

Minor CMake improvement that becomes a major improvement on Windows,
because for some reason OpenEXR on Windows always crashes if you mix
release/debug builds (e.g. release OpenEXR + debug Olive and vice versa).
This ensures that as long as you have both release and debug (which you
will if you installed from vcpkg), CMake will link the correct lib and
prevent crashes.

cmake/FindOpenEXR.cmake

@@ -118,13 +118,21 @@ set (_openexr_components IlmThread IlmImf Imath Iex Half)
 foreach (COMPONENT ${_openexr_components})
     string (TOUPPER ${COMPONENT} UPPERCOMPONENT)
     # First try with the version embedded
-    find_library (OPENEXR_${UPPERCOMPONENT}_LIBRARY
+    find_library (OPENEXR_${UPPERCOMPONENT}_LIBRARY_RELEASE
                   NAMES ${COMPONENT}-${OPENEXR_VERSION_MAJOR}_${OPENEXR_VERSION_MINOR}
                         ${COMPONENT}
-                        ${COMPONENT}-${OPENEXR_VERSION_MAJOR}_${OPENEXR_VERSION_MINOR}_d
+                  HINTS ${OPENEXR_LIBRARY_DIR} $ENV{OPENEXR_LIBRARY_DIR}
+                        ${GENERIC_LIBRARY_PATHS} )
+
+    find_library (OPENEXR_${UPPERCOMPONENT}_LIBRARY_DEBUG
+                  NAMES ${COMPONENT}-${OPENEXR_VERSION_MAJOR}_${OPENEXR_VERSION_MINOR}_d
                         ${COMPONENT}_d
                   HINTS ${OPENEXR_LIBRARY_DIR} $ENV{OPENEXR_LIBRARY_DIR}
                         ${GENERIC_LIBRARY_PATHS} )
+
+    set(OPENEXR_${UPPERCOMPONENT}_LIBRARY
+      optimized ${OPENEXR_${UPPERCOMPONENT}_LIBRARY_RELEASE}
+      debug ${OPENEXR_${UPPERCOMPONENT}_LIBRARY_DEBUG})
 endforeach ()
 
 find_package_handle_standard_args (OpenEXR