sane-backends: import from oldpackages and update

sane-backends: import from oldpackages and update

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>