Origin: http://marc.info/?l=openbsd-ports&m=142090828929750&w=2
* main.c: Call exit(1) when out of memory to avoid dereferencing null
pointers when gc's malloc fails.
* alloc.h: Replacements for w3m's allocation macros which add
overflow detection and concentrate the macros in one file.
* indep.h, libwc/charset.c, libwc/status.c, matrix.c: Use the
overflow-detecting allocation macros from alloc.h.
