Log Message:
Fix xmms to build on i386 Mac OS X 10.4.7.

Remove the _ SYMBOL_PREFIX, as OpenDarwin ports does.

Disable i386 assembly optimizations.

Add OSX code to raise priority.

_INSTALL_UNSTRIPPED=yes on OSX.  Otherwise plugins, such as
lib/xmms/Input/libmpg123.so fail to load because the OSX linker can't
find symbols such as _xmms_get_gentitle_format from xmms/main.c.