Source code was inconsistent on how they were referencing
include files in include/sane. In certain cases, sane/sane.h
and sane/saneopts.h was really including external copies (with
some preprocessor implementations anyways).
Global replace of u_int??_t with C9x standard based uintxx_t
in order to remove some tricky and overlapping portability logic
from acinclude.m4 and leave it in only m4/stdint.m4.
to copy it over and over again. Changed header inclusion order in backend
files to include backend.h after sanei_backend.h. Based on a patch from stef
<stef-listes@wanadoo.fr>.