Treat Haiku as BeOS in CMakeLists.txt ... this lets CD-ROM support build, etc.

CMakeLists.txt

@@ -26,6 +26,11 @@ IF (CMAKE_SYSTEM MATCHES OS2)
     SET(OS2 TRUE)
 ENDIF (CMAKE_SYSTEM MATCHES OS2)
 
+# For now, Haiku and BeOS are the same, as far as the build system cares.
+IF(HAIKU AND NOT BEOS)
+    SET(BEOS TRUE)
+ENDIF(HAIKU AND NOT BEOS)
+
 IF(CMAKE_SYSTEM_NAME STREQUAL "SunOS")
     SET(SOLARIS TRUE)
 ENDIF(CMAKE_SYSTEM_NAME STREQUAL "SunOS")