UNALIGNED is used in structures and must *always* be defined.

"Always" means "even on compilers that don't define __GNUC__".  If we
don't want

	#if X
	{nothing}
	#else
	#undef UNALIGNED
	#define UNALIGNED	__attribute__((packed))
	#endif

because it's backwards, just do

	#if !(X)
	#undef UNALIGNED
	#define UNALIGNED	__attribute__((packed))
	#endif
AoE: add version 1 decoder (GH #298)

The sample capture was produced with two Linux hosts (aoetools version
36, kernel module version 85, vblade version 21). One of the hosts
exported a 1MB block device containing a freshly created filesystem and
the other mounted it, wrote a small file and then unmounted.