support giflib 5.0+

--- image/gif.c.orig	Tue Mar  7 06:59:56 2000
+++ image/gif.c	Sat Mar 28 17:26:33 2015
@@ -15,6 +15,7 @@
 
 #ifdef USE_GIF
 
+#include <stdlib.h>
 #include "image.h"
 #include <gif_lib.h>
 
@@ -50,7 +51,7 @@ gifLoad(fullname, name, verbose)
 	ColorMapObject *ColorMap;
 	GifColorType *ColorMapEntry;
 
-	GifFile = DGifOpenFileName(fullname);
+	GifFile = DGifOpenFileName(fullname, NULL);
 	if (GifFile == NULL)
 		return NULL;
 
@@ -87,13 +88,13 @@ gifLoad(fullname, name, verbose)
 	/* Scan the content of the GIF file and load the image(s) in: */
 	do {
 		if (DGifGetRecordType(GifFile, &RecordType) == GIF_ERROR) {
-			PrintGifError();
+			fprintf(stderr, "giflib error: %s\n", GifErrorString(GifFile->Error));
 			exit(-1);
 		}
 		switch (RecordType) {
 		case IMAGE_DESC_RECORD_TYPE:
 			if (DGifGetImageDesc(GifFile) == GIF_ERROR) {
-				PrintGifError();
+				fprintf(stderr, "giflib error: %s\n", GifErrorString(GifFile->Error));
 				exit(-1);
 			}
 			Row = GifFile->Image.Top; /* Image Position relative to Screen. */
@@ -113,7 +114,7 @@ gifLoad(fullname, name, verbose)
 							     j += InterlacedJumps[i]) {
 					if (DGifGetLine(GifFile, &ScreenBuffer[j][Col],
 					    Width) == GIF_ERROR) {
-					    PrintGifError();
+					    fprintf(stderr, "giflib error: %s\n", GifErrorString(GifFile->Error));
 					    exit(-1);
 					}
 				}
@@ -122,7 +123,7 @@ gifLoad(fullname, name, verbose)
 				for (i = 0; i < Height; i++) {
 					if (DGifGetLine(GifFile, &ScreenBuffer[Row++][Col],
 					    Width) == GIF_ERROR) {
-						PrintGifError();
+					    	fprintf(stderr, "giflib error: %s\n", GifErrorString(GifFile->Error));
 						exit(-1);
 					}
 				}
@@ -131,7 +132,7 @@ gifLoad(fullname, name, verbose)
 		case EXTENSION_RECORD_TYPE:
 			/* Skip any extension blocks in file: */
 			if (DGifGetExtension(GifFile, &ExtCode, &Extension) == GIF_ERROR) {
-				PrintGifError();
+				fprintf(stderr, "giflib error: %s\n", GifErrorString(GifFile->Error));
 				exit(-1);
 			}
 			/* very adhoc transparency support */
@@ -141,7 +142,7 @@ gifLoad(fullname, name, verbose)
 			}
 			while (Extension != NULL) {
 				if (DGifGetExtensionNext(GifFile, &Extension) == GIF_ERROR) {
-					PrintGifError();
+					fprintf(stderr, "giflib error: %s\n", GifErrorString(GifFile->Error));
 					exit(-1);
 				}
 			}
@@ -179,8 +180,8 @@ gifLoad(fullname, name, verbose)
 			pixline[x] = GifRow[x];
 	}
 
-	if (DGifCloseFile(GifFile) == GIF_ERROR) {
-		PrintGifError();
+	if (DGifCloseFile(GifFile, NULL) == GIF_ERROR) {
+		fprintf(stderr, "giflib error: %s\n", GifErrorString(GifFile->Error));
 		exit(-1);
 	}
 
@@ -196,11 +197,11 @@ gifIdent(fullname, name)
 	GifFileType *gifp;
 	int ret;
 
-	gifp = DGifOpenFileName(fullname);
+	gifp = DGifOpenFileName(fullname, NULL);
 	if (gifp == NULL)
 		ret = 0;
 	else {
-		DGifCloseFile(gifp);
+		DGifCloseFile(gifp, NULL);
 		tellAboutImage(name);
 		ret = 1;
 	}