sane-backends: update to 1.0.29

- Migrate libusb dependency back to libsane
  (virtually all useful backends for OpenWrt would need it anyway)
- Disabled new usb-record-replay feature (avoid libxml2 dep)
- Disabled new escl backend (network-only backend are not too useful
  for OpenWrt and it requires libcurl, libnetsnmp, libavahi and libxml2)
- Workaround sane-daemon/postinst installation on Imagebuild
- Enabled backends kvs40xx and mustek_usb2 (fixed upstream)
- Fix bigendian compilation
  (https://gitlab.com/sane-project/backends/-/merge_requests/329)
- Fix missing std::round() for uclibc
  (https://gitlab.com/sane-project/backends/issues/237)
- Fixes FS#2685: coldplug was running before usblp was loaded. Now
  it grants access do usblp when a device using it is plugged.

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

utils/sane-backends/patches/002-remove-uneeded.patch

@@ -1,11 +1,11 @@
 --- a/Makefile.in
 +++ b/Makefile.in
-@@ -442,7 +442,7 @@ target_alias = @target_alias@
+@@ -448,7 +448,7 @@ target_alias = @target_alias@
  top_build_prefix = @top_build_prefix@
  top_builddir = @top_builddir@
  top_srcdir = @top_srcdir@
 -SUBDIRS = include lib sanei backend frontend tools doc po testsuite
 +SUBDIRS = include lib sanei backend frontend
  DIST_SUBDIRS = include lib sanei backend frontend tools doc po japi testsuite
- dist_doc_DATA = AUTHORS ChangeLog COPYING LICENSE NEWS PROBLEMS PROJECTS \
-  README README.aix README.beos README.darwin README.djpeg README.freebsd \
+ dist_doc_DATA = AUTHORS COPYING LICENSE NEWS PROBLEMS PROJECTS README \
+ 	README.aix README.beos README.darwin README.djpeg \