DirectFB no longer defines DSPF_RGB15 since it was really just a 
ghetto shortcut to DSPF_ARGB1555.

http://bugs.gentoo.org/show_bug.cgi?id=77034
http://www.directfb.org/index.php/viewcvs.cgi/DirectFB/include/directfb.h.diff?r1=1.194&r2=1.195

--- ClanLib-0.6.5/Sources/Display/Display/DirectFB/target_directfb.cpp
+++ ClanLib-0.6.5/Sources/Display/Display/DirectFB/target_directfb.cpp
@@ -147,7 +147,7 @@
     {
     case DSPF_A8:
       return 0;
-    case DSPF_RGB15:
+    case DSPF_ARGB1555:
       return 0x007c00;
     case DSPF_RGB16:
       return 0x00f800;
@@ -170,7 +168,7 @@
     {
     case DSPF_A8:
       return 0;
-    case DSPF_RGB15:
+    case DSPF_ARGB1555:
       return 0x0003e0;
     case DSPF_RGB16:
       return 0x0007e0;
@@ -193,7 +189,7 @@
     {
     case DSPF_A8:
       return 0;
-    case DSPF_RGB15:
+    case DSPF_ARGB1555:
     case DSPF_RGB16:
       return 0x00001f;
     case DSPF_RGB24:
@@ -215,7 +210,7 @@
     {
     case DSPF_A8:
       return 0xff;
-    case DSPF_RGB15:
+    case DSPF_ARGB1555:
     case DSPF_RGB16:
     case DSPF_RGB24:
     case DSPF_RGB32: