Just Need runtime tests

* libsane dependency on libusb moved to those drivers that requires it
* clean up some ./configure args
* added saned-ricoh2 for new backend
* enabled saned-gphoto2 (after c8fbe26c53)
* disabled kvs40xx and mustek_usb2 that requires pthread while the issue is
not solved (https://gitlab.com/sane-project/backends/issues/153)
* patches refreshed:
 - 002-remove-uneeded.patch
* patches dropped:
 - 031-fix_uclibc.patch
 - 050-remove_linked_libs_for_unused_preload.patch (with --disable-preload)

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>

While scanning, sane unbinds usb device from usblp module. This
patch creates a saned wrapper that keep track of all usb devices
binded to usblp before saned is launched and rebind them back
if not still bound after saned exits.

This workaround is only effective if saned is launched by a super
daemon like xinetd as it needs to exit after scan job finish. If
not, printing will not be available while saned service is running.

Write access to /sys/bus/usb/drivers/usblp/bind is required. So,
normally it would require root access.

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>

Changes since oldpackages:
- updated to 1.0.25
  * most of openwrt patches are upstreamed now
- cups dependency was completely removed
- small musl patch
- small uclibc patch
- removed link to extra libraries in libsane (used only
  for preload backends)
- sane-libs and sane-backends merged and exploded into
  individual packages for each backend:
  * libsane for sane library (which backends should dep on)
  * sane-daemon for saned daemon
  * sane-xxx for sane backend for xxx
  ** each backend has its own custom dep libraries
  * sane-backends-all (with no files) that deps on all backends
  * sane-qcam is only available for x86/x86_64
  ** other archs does not implement inb/outb (at least in musl)

Now it is possible to use SANE with much less FS space (KB
instead of MB).

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>

Changes since oldpackages:
- cups dependency was completely removed
  * This also happened in sane trunk version
- small musl patch
- added detection of inb,outb (link error with musl)
  * this also removes hack 020-non-i386-qcam.patch
- fix for segfault when using sane-test backend
- removed link to extra libraries in libsane (used only
  for preload backends)
- added format-security fix
- sane-libs and sane-backends merged and exploded into
  individual packages for each backend:
  * libsane for sane library (which backends should dep on)
  * sane-daemon for saned daemon
  * sane-xxx for sane backend for xxx
  ** each backend has its own custom dep libraries
  * sane-backends-all (with no files) that deps on all backends
  * sane-qcam is only available for x86/x86_64
  ** other archs does not implement inb/outb (at least in musl)

Now it is possible to use SANE with much less FS space (KB
instead of MB).

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>