more warning fixes.

sprinkle a few 'const char*'s around to remove warnings 
about discarding qualifiers in imbuf code.

source/blender/blenlib/BLI_blenlib.h

@@ -173,7 +173,7 @@ void BLI_clean(char *path);
 	 * @param str The string to be duplicated
 	 * @retval Returns the duplicated string
 	 */
-char* BLI_strdup(char *str);
+char* BLI_strdup(const char *str);
 
 	/**
 	 * Duplicates the first @a len bytes of cstring @a str 

source/blender/blenlib/intern/util.c

@@ -633,7 +633,7 @@ char *BLI_strdupn(char *str, int len) {
 	
 	return n;
 }
-char *BLI_strdup(char *str) {
+char *BLI_strdup(const char *str) {
 	return BLI_strdupn(str, strlen(str));
 }
 

source/blender/imbuf/IMB_imbuf.h

@@ -158,7 +158,7 @@ struct ImBuf *IMB_testiffname(char *naam,int flags);
  *
  * @attention Defined in readimage.c
  */
-struct ImBuf *IMB_loadiffname(char *naam, int flags);
+struct ImBuf *IMB_loadiffname(const char *naam, int flags);
 
 /**
  *
@@ -258,7 +258,7 @@ int IMB_anim_get_duration(struct anim *anim);
  *
  * @attention Defined in anim.c
  */
-struct anim * IMB_open_anim(char * name, int ib_flags);
+struct anim * IMB_open_anim(const char * name, int ib_flags);
 void IMB_close_anim(struct anim * anim);
 
 /**

source/blender/imbuf/intern/IMB_jpeg.h

@@ -45,7 +45,7 @@ struct jpeg_compress_struct;
 
 int imb_is_a_jpeg(unsigned char *mem);
 int imb_savejpeg(struct ImBuf * ibuf, char * name, int flags);
-struct ImBuf * imb_ibJpegImageFromFilename (char * filename, int flags);
+struct ImBuf * imb_ibJpegImageFromFilename (const char * filename, int flags);
 struct ImBuf * imb_ibJpegImageFromMemory (unsigned char * buffer, int size, int flags);
 
 #endif

source/blender/imbuf/intern/anim.c

@@ -338,12 +338,12 @@ void IMB_close_anim(struct anim * anim) {
 }
 
 
-struct anim * IMB_open_anim(char * name, int ib_flags) {
+struct anim * IMB_open_anim( const char * name, int ib_flags) {
 	struct anim * anim;
 
 	anim = (struct anim*)MEM_callocN(sizeof(struct anim), "anim struct");
 	if (anim != NULL) {
-		strcpy(anim->name, name);
+		strcpy(anim->name, name);  /* fixme: possible buffer overflow here? */
 		anim->ib_flags = ib_flags;
 	}
 	return(anim);

source/blender/imbuf/intern/jpeg.c

@@ -345,7 +345,7 @@ static ImBuf * ibJpegImageFromCinfo(struct jpeg_decompress_struct * cinfo, int f
 	return(ibuf);
 }
 
-ImBuf * imb_ibJpegImageFromFilename (char * filename, int flags)
+ImBuf * imb_ibJpegImageFromFilename (const char * filename, int flags)
 {
 	struct jpeg_decompress_struct _cinfo, *cinfo = &_cinfo;
 	struct jpeg_error_mgr jerr;

source/blender/imbuf/intern/readimage.c

@@ -268,7 +268,7 @@ struct ImBuf *IMB_loadifffile(int file, int flags) {
 }
 
 
-struct ImBuf *IMB_loadiffname(char *naam, int flags) {
+struct ImBuf *IMB_loadiffname(const char *naam, int flags) {
 	int file;
 	struct ImBuf *ibuf;
 	int buf[1];