root: 6.08.02 -> 6.09.02

This also fixes breakage on darwin due to LLVM4.0 migration.

I had to enable opengl because otherwise macOS build is broken.
See root commit 23f8871c7 ('Do not include OpenGL directly but use our
TGLIncludes for that purpose.')

I've enabled xml because TUnfold depends on it.

pkgs/applications/science/misc/root/sw_vers.patch

@@ -25,7 +25,7 @@ diff --git a/cmake/modules/SetUpMacOS.cmake b/cmake/modules/SetUpMacOS.cmake
 -                  COMMAND cut -d . -f 2
 -                  OUTPUT_VARIABLE MACOSX_MINOR OUTPUT_STRIP_TRAILING_WHITESPACE)
 -
--  if(MACOSX_VERSION VERSION_GREATER 10.7 AND ${CMAKE_CXX_COMPILER_ID} STREQUAL Clang)
+-  if(MACOSX_VERSION VERSION_GREATER 10.7 AND ${CMAKE_CXX_COMPILER_ID} MATCHES Clang)
      set(libcxx ON CACHE BOOL "Build using libc++" FORCE)
 -  endif()