utils: removed unused functions

Removed all allocation functions, xwrite(), xread(), ARRAY_SIZE().
Those have been superseded by GLib.

src/decoder/wavpack_plugin.c

@@ -27,6 +27,8 @@
 
 #include <assert.h>
 #include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
 
 /* pick 1020 since its devisible for 8,16,24, and 32-bit audio */
 #define CHUNK_SIZE		1020