src/sfendian.h : Add big endian versions of H2BE_16 and H2BE_32.
src/test_cart_var.c : Minor fixes.
src/ : Add tests for psf_put_be32() and psf_put_be64().
Add functions psf_get_be(16|32|64) with tests.

These are needed for platforms where un-aligned accesses cause bus
faults.
ALAC/ : Replace all un-aligned accesses with safe alternatives.
ChangeLog : Update entry.