* Improved Mac OS X build support.

* Dropped support for Mac OS X 10.2 to simplify things.  If anyone still
  needs this version supported let me know.

Makefile

@@ -284,10 +284,6 @@ ifeq ($(PLATFORM),darwin)
   LDFLAGS=
   OPTIMIZE=
   
-  ifndef MACOSX_SDK_DIR
-  	MACOSX_SDK_DIR="/Developer/SDKs/MacOSX10.5.sdk"
-  endif
-
   # building the QVMs on MacOSX is broken, atm.
   BUILD_GAME_QVM=0
   
@@ -296,33 +292,28 @@ ifeq ($(PLATFORM),darwin)
     BASE_CFLAGS += -arch ppc -DSMP \
       -DMAC_OS_X_VERSION_MIN_REQUIRED=1020 -nostdinc \
       -F"$(MACOSX_SDK_DIR)"/System/Library/Frameworks \
-      -I"$(MACOSX_SDK_DIR)"/usr/lib/gcc/i686-apple-darwin9/4.0.1/include \
+      -I"$(MACOSX_SDK_DIR)"/"$(MACOSX_SDK_INC)" \
       -isystem "$(MACOSX_SDK_DIR)"/usr/include
     LDFLAGS += -arch ppc \
-      -L"$(MACOSX_SDK_DIR)"/usr/lib/gcc/darwin/4.0 \
+      -L"$(MACOSX_SDK_DIR)"/"$(MACOSX_SDK_LIB)" \
       -F"$(MACOSX_SDK_DIR)"/System/Library/Frameworks \
       -Wl,-syslibroot,"$(MACOSX_SDK_DIR)"
     ARCH=ppc
 
-    # OS X 10.2 sdk lacks dlopen() so ded would need libSDL anyway
-#    BUILD_SERVER=0
-
   else
-
   ifeq ($(BUILD_MACOSX_UB),i386)
     CC=gcc-4.0
     BASE_CFLAGS += -arch i386 -DSMP \
       -mmacosx-version-min=10.4 \
       -DMAC_OS_X_VERSION_MIN_REQUIRED=1040 -nostdinc \
       -F"$(MACOSX_SDK_DIR)"/System/Library/Frameworks \
-      -I"$(MACOSX_SDK_DIR)"/usr/lib/gcc/i686-apple-darwin9/4.0.1/include \
+      -I"$(MACOSX_SDK_DIR)"/"$(MACOSX_SDK_INC)" \
       -isystem "$(MACOSX_SDK_DIR)"/usr/include
     LDFLAGS = -arch i386 -mmacosx-version-min=10.4 \
-      -L"$(MACOSX_SDK_DIR)"/usr/lib/gcc/i686-apple-darwin9/4.0.1 \
+      -L"$(MACOSX_SDK_DIR)"/"$(MACOSX_SDK_LIB)" \
       -F"$(MACOSX_SDK_DIR)"/System/Library/Frameworks \
       -Wl,-syslibroot,"$(MACOSX_SDK_DIR)"
     ARCH=i386
-#    BUILD_SERVER=0
   else
     # for whatever reason using the headers in the MacOSX SDKs tend to throw
     # errors even though they are identical to the system ones which don't