Add a cross-platform dlopen() implementation which searches on *nix for

the library since many Linux distros today do not symlink to the *.so file
(I mean you Ubuntu!)

src/xpdev/xp_dl.c

+#include "dirwrap.h"
+#include "xp_dl.h"
+
+#if defined(__unix__)
+xp_dlopen(const char *name, int mode, int major, int minor)
+{
+	char		fname[MAX_PATH+1];
+	dll_handle	ret=NULL;
+	int			i;
+
+	/* Try for exact version match */
+	sprintf(fname, "%s.%d.%d", name, major, minor);
+	if((dll_handle=dlopen(fname, mode))!=NULL)
+		return(ret);
+
+	/* Try for major version match */
+	sprintf(fname, "%s.%d", name, major);
+	if((dll_handle=dlopen(fname, mode))!=NULL)
+		return(ret);
+
+	/* Try for preferred match (symlink) */
+	if((dll_handle=dlopen(name, mode))!=NULL)
+		return(ret);
+
+	/* Try all previous major versions */
+	for(i=major-1; i>=0; i--) {
+		sprintf(fname, "%s.%d", name, i);
+		if((dll_handle=dlopen(fname, mode))!=NULL)
+			return(ret);
+	}
+
+	return(NULL);
+}
+#endif
+
+
+#endif

src/xpdev/xp_dl.h

+#ifndef _XP_DL_H_
+#define _XP_DL_H_
+
+#include "wrapdll.h"
+
+#if defined(__unix__)
+	#include <dlfcn.h>
+
+	typedef void * dll_handle;
+	#define xp_dlsym(handle, name)				dlsym(handle, name)
+	#define xp_dlclose(handle)					dlclose(handle)
+#elif defined(_WIN32)
+	#include <Winbase.h>
+
+	typedef HMODULE WINAPI dll_handle;
+	#define xp_dlopen(name, mode, major, minor)	LoadLibrary(name)
+	#define xp_dlsym(handle, name)				((void *)GetProcAddress(handle, name))
+	#define xp_dlclose(handle)					(FreeLibrary(handle)?0:-1)
+
+	/* Unused values for *nix compatability */
+	enum {
+		 RTLD_LAZY
+		,RTLD_NOW
+		,RTLD_GLOBAL
+		,RTLD_LOCAL
+		,RTLD_TRACE
+	};
+#endif
+
+DLLEXPORT void* DLLCALL xp_dlopen(const char *name, int mode, int major, int minor);
+
+#endif