commit 26848fe8da158b7eb903dae5ea2963f8aa09f38a
Author: Sam Thursfield <sam.thursfield@codethink.co.uk>
Date:   Tue Jan 12 16:01:54 2016 +0100

    FindPNG: Create an imported PNG::PNG target
    
    Imported targets are now the recommended way of dealing with external
    library dependencies.

diff --git a/Modules/FindPNG.cmake b/Modules/FindPNG.cmake
index 7cf3f22..0a7bf16 100644
--- a/Modules/FindPNG.cmake
+++ b/Modules/FindPNG.cmake
@@ -8,6 +8,10 @@
 #
 # This module searches libpng, the library for working with PNG images.
 #
+# It creates the following imported target:
+#
+#   PNG::PNG
+#
 # It defines the following variables
 #
 # ``PNG_INCLUDE_DIRS``
@@ -105,6 +109,13 @@ if(ZLIB_FOUND)
         endif()
       endif ()
 
+      add_library(PNG::PNG UNKNOWN IMPORTED)
+      set_target_properties(PNG::PNG PROPERTIES
+          IMPORTED_LOCATION ${PNG_LIBRARY}
+          INTERFACE_COMPILE_DEFINITIONS "${PNG_DEFINITIONS}"
+          INTERFACE_INCLUDE_DIRECTORIES ${PNG_INCLUDE_DIRS}
+          INTERFACE_LIBRARIES ${PNG_LIBRARIES}
+          )
   endif ()
 
   if (PNG_PNG_INCLUDE_DIR AND EXISTS "${PNG_PNG_INCLUDE_DIR}/png.h")