Allow pointers to append; Fix strconv stuff; new_slice allows for capacity

core/strings.odin

@@ -1,8 +1,8 @@
 new_c_string :: proc(s: string) -> ^byte {
-	c := new_c_string(byte, s.count+1);
+	c := new_slice(byte, s.count+1);
 	copy(c, cast([]byte)s);
 	c[s.count] = 0;
-	return c;
+	return c.data;
 }
 
 to_odin_string :: proc(c: ^byte) -> string {