Fix case of Libraries.txt.
https://github.com/DentonW/DevIL/pull/71
--- src-IL/CMakeLists.txt.orig	2017-01-01 18:03:56.000000000 -0600
+++ src-IL/CMakeLists.txt	2020-07-05 09:20:01.000000000 -0500
@@ -43,7 +43,7 @@
 		else(UNICODE)
 			set(DevIL_RSRC ${DevIL_RSRC} "msvc/resources/IL Logo.ico" "msvc/IL.rc")
 		endif(UNICODE)
-        set(DevIL_TXT ${DevIL_TXT} ../AUTHORS ../ChangeLog ../CREDITS ../libraries.txt ../README.md ../README.cmake ../TODO)
+        set(DevIL_TXT ${DevIL_TXT} ../AUTHORS ../ChangeLog ../CREDITS ../Libraries.txt ../README.md ../README.cmake ../TODO)
 #		SET(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} /NODEFAULTLIB:msvcrt.lib ")
 		set(CMAKE_C_FLAGS_RELEASE "/MT /O2")
 	else(BUILD_SHARED_LIBS)