use size_t for MEM_allocN_len as well as some of its callers

intern/guardedalloc/MEM_guardedalloc.h

@@ -66,7 +66,7 @@ extern "C" {
 	/** Returns the lenght of the allocated memory segment pointed at
 	 * by vmemh. If the pointer was not previously allocated by this
 	 * module, the result is undefined.*/
-	int MEM_allocN_len(void *vmemh);
+	size_t MEM_allocN_len(void *vmemh);
 
 	/**
 	 * Release memory previously allocatred by this module. 

intern/guardedalloc/intern/mallocn.c

@@ -220,7 +220,7 @@ void MEM_set_memory_debug(void)
 	malloc_debug_memset= 1;
 }
 
-int MEM_allocN_len(void *vmemh)
+size_t MEM_allocN_len(void *vmemh)
 {
 	if (vmemh) {
 		MemHead *memh= vmemh;

source/blender/blenkernel/intern/library.c

@@ -650,7 +650,7 @@ void *copy_libblock(void *rt)
 	ID *idn, *id;
 	ListBase *lb;
 	char *cp, *cpn;
-	int idn_len;
+	size_t idn_len;
 	
 	id= rt;
 

source/blender/blenkernel/intern/sequencer.c

@@ -586,7 +586,7 @@ void reload_sequence_new_file(Scene *scene, Sequence * seq)
 
 	if (seq->type == SEQ_IMAGE) {
 		/* Hack? */
-		int olen = MEM_allocN_len(seq->strip->stripdata)/sizeof(struct StripElem);
+		size_t olen = MEM_allocN_len(seq->strip->stripdata)/sizeof(struct StripElem);
 		seq->len = olen;
 		seq->len -= seq->anim_startofs;
 		seq->len -= seq->anim_endofs;

source/blender/blenloader/intern/readfile.c

@@ -1357,7 +1357,8 @@ static void test_pointer_array(FileData *fd, void **mat)
 #else
 	long long *lpoin, *lmat;
 #endif
-	int len, *ipoin, *imat;
+	int *ipoin, *imat;
+	size_t len;
 
 		/* manually convert the pointer array in
 		 * the old dna format to a pointer array in