sanei/sanei_tcp.c, sanie/sanei_udp.c: Improve portablity by
removing usage of MSG_WAITALL since not all platforms support
that (cygwin). Default is to be blocking anyways. Changed
usage of MSG_NOTWAIT to use fcntl() function as needed as well.
* configure.in, lib/Makefile.in, lib/strcasestr.c: Add internal
strcasestr() for platforms missing it (cygwin).
* pixma_common.c: My source match header prototype for picky
compilers (cygwin).
* backend/umax_pp_mid.c: Allow BACKEND_NAME to be filename
yet debug to be SANE_DEBUG_UMAX_PP to match man page.