Not all pthreads implementations use an integer type for pthread_t.
As a matter of fact, POSIX has explicitly withdrawn the requirement
that it must be an arithmatic type.
The musl C library uses a `struct __pthread *` which triggered the
warnings. As of this change, sanei_thread.h works around this by
providing two new macros to help keep this issue out of sight. All
backends have been changed to use these macros.
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>.