DRTVWR-476: Help DirectX.cmake cope with multiple SDK versions.

First, get rid of ancient cruft in the find_path() calls: on a 64-bit system,
"$ENV{PROGRAMFILES}" expands to the 64-bit 'Program Files' directory rather
than the 32-bit 'Program Files (x86)' directory, and none of the ancient cruft
would be found there anyway.

Empirically, find_path(dxdiag.h) is able to find the file using environment
variables (INCLUDE from VS variables?), so it doesn't need the specific
pathnames coded into that call.

Once we find DIRECTX_INCLUDE_DIR, don't immediately insert it into
include_directories: we've had troubles with incompatible Windows SDK versions
(compile errors in Microsoft header files!) when DIRECTX_INCLUDE_DIR preceded
the Windows SDK directory in the include path.

The DIRECTX_FIND_QUIETLY logic seemed backwards: the message(STATUS) output was
emitted only when DIRECTX_FIND_QUIETLY was false. Reverse that.

The ancient cruft in find_path(dxguid.lib) was causing it to find the wrong
(very old) DirectX library. Remove ancient cruft. But empirically, without
that, even once we've found DIRECTX_INCLUDE_DIR, CMake could not implicitly
find dxguid.lib. If the DirectX directory hierarchy were structured as
.../version/Include and .../version/Lib, a relative pathname would have been
sufficient hint. Unfortunately it's structured as .../Include/version and
.../Lib/version, so a relative pathname would have to include the specific
version. Instead, replace "/Include/" with "/Lib/". But even then, we have to
drill down to the architecture-specific subdirectory based on ADDRESS_SIZE.

indra/cmake/DirectX.cmake

 # -*- cmake -*-
 
 if (WINDOWS)
-  find_path(DIRECTX_INCLUDE_DIR dxdiag.h
-            "$ENV{DXSDK_DIR}/Include"
-            "$ENV{PROGRAMFILES}/Microsoft DirectX SDK (June 2010)/Include"
-            "$ENV{PROGRAMFILES}/Microsoft DirectX SDK (August 2009)/Include"
-            "$ENV{PROGRAMFILES}/Microsoft DirectX SDK (March 2009)/Include"
-            "$ENV{PROGRAMFILES}/Microsoft DirectX SDK (August 2008)/Include"
-            "$ENV{PROGRAMFILES}/Microsoft DirectX SDK (June 2008)/Include"
-            "$ENV{PROGRAMFILES}/Microsoft DirectX SDK (March 2008)/Include"
-            "$ENV{PROGRAMFILES}/Microsoft DirectX SDK (November 2007)/Include"
-            "$ENV{PROGRAMFILES}/Microsoft DirectX SDK (August 2007)/Include"
-            "C:/DX90SDK/Include"
-            "$ENV{PROGRAMFILES}/DX90SDK/Include"
-            )
+  find_path(DIRECTX_INCLUDE_DIR dxdiag.h)
   if (DIRECTX_INCLUDE_DIR)
-    include_directories(${DIRECTX_INCLUDE_DIR})
-    if (DIRECTX_FIND_QUIETLY)
+    if (NOT DIRECTX_FIND_QUIETLY)
       message(STATUS "Found DirectX include: ${DIRECTX_INCLUDE_DIR}")
-    endif (DIRECTX_FIND_QUIETLY)
+    endif (NOT DIRECTX_FIND_QUIETLY)
   else (DIRECTX_INCLUDE_DIR)
     message(FATAL_ERROR "Could not find DirectX SDK Include")
   endif (DIRECTX_INCLUDE_DIR)
 
-
-  find_path(DIRECTX_LIBRARY_DIR dxguid.lib
-            "$ENV{DXSDK_DIR}/Lib/x86"
-            "$ENV{PROGRAMFILES}/Microsoft DirectX SDK (June 2010)/Lib/x86"
-            "$ENV{PROGRAMFILES}/Microsoft DirectX SDK (August 2009)/Lib/x86"
-            "$ENV{PROGRAMFILES}/Microsoft DirectX SDK (March 2009)/Lib/x86"
-            "$ENV{PROGRAMFILES}/Microsoft DirectX SDK (August 2008)/Lib/x86"
-            "$ENV{PROGRAMFILES}/Microsoft DirectX SDK (June 2008)/Lib/x86"
-            "$ENV{PROGRAMFILES}/Microsoft DirectX SDK (March 2008)/Lib/x86"
-            "$ENV{PROGRAMFILES}/Microsoft DirectX SDK (November 2007)/Lib/x86"
-            "$ENV{PROGRAMFILES}/Microsoft DirectX SDK (August 2007)/Lib/x86"
-            "C:/DX90SDK/Lib"
-            "$ENV{PROGRAMFILES}/DX90SDK/Lib"
-            )
+  # dxhint isn't meant to be the hard-coded DIRECTX_LIBRARY_DIR, we're just
+  # suggesting it as a hint to the next find_path(). The version is embedded
+  # in the DIRECTX_INCLUDE_DIR path string after Include and Lib, which is why
+  # we don't just append a relative path: if there are multiple versions
+  # installed on the host, we need to be sure we're using THE SAME version.
+  string(REPLACE "/Include/" "/Lib/" dxhint "${DIRECTX_INCLUDE_DIR}")
+  if (ADDRESS_SIZE EQUAL 32)
+    set(archdir x86)
+  else()
+    set(archdir x64)
+  endif()
+  string(APPEND dxhint "/${archdir}")
+  find_path(DIRECTX_LIBRARY_DIR dxguid.lib HINTS "${dxhint}")
   if (DIRECTX_LIBRARY_DIR)
-    if (DIRECTX_FIND_QUIETLY)
-      message(STATUS "Found DirectX include: ${DIRECTX_LIBRARY_DIR}")
-    endif (DIRECTX_FIND_QUIETLY)
+    if (NOT DIRECTX_FIND_QUIETLY)
+      message(STATUS "Found DirectX library: ${DIRECTX_LIBRARY_DIR}")
+    endif (NOT DIRECTX_FIND_QUIETLY)
   else (DIRECTX_LIBRARY_DIR)
     message(FATAL_ERROR "Could not find DirectX SDK Libraries")
   endif (DIRECTX_LIBRARY_DIR)