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As a matter of fact, POSIX has explicitly withdrawn the requirement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.
This gets rid of a number of obsoleted macros and replaces RETSIGTYPE
with a void literal which can be assumed for C89 and later.
This changeset was prepared using autoupdate and modified to get rid of
whitespace and doubled [] changes. Changes to acinclude.m4 were added
by hand.
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).
Olaf Meeuwissen