This library crashes on out-of-memory (NULL pointer dereference).
There's not much useful MPD can do in such a situation, so let's
explicitly abort instead, just like GLib does.
In mingw32, int16_t is not defined by sys/types.h, but it is by stdint.h,
and it is in the int16_t man page as being defined in stdint.h. Thanks to
mithi for help debugging.
