update lib/snprintf.c to newer version from LPRng

The old version is licensed under the Artistic License 1.0 which isn't
compatible with the GPL and arguably non-free.

Signed-off-by: Nils Philippsen <nils@redhat.com>
 * fix trailing whitespace
update ChangeLog
epjitsu backend v25

- initial support for fi-65F
- initial support for S1100
fix gain calibration

- enable GMMENB during calibration scan in simple_scan, otherwise there
  is 'color clamping' with default asic table
fix #314694

- make sanei_config testsuite handle out of source builds by using
  SANE_CONFIG_DIR
epjitsu backend v26

- add resolution scaling
- fix 150 dpi settings for fi-60F and fi-65F
- make adf_height_padding variable
- make white_factor variable
canon_dr backend v47

initial DR-G1130 support
add usb ids for many recent scanners
add batch-print option to scanimage

Enables better interoperability with tesseract.
Code by Jeff Breidenbach jeff@jab.org
change exit status of scanimage

If we have successfully scanned at least one image
during a batch scan, don't return SANE_STATUS_NO_DOCS.
Code by Jeff Breidenbach jeff@jab.org
changelog
new scanners Canon Pixma E400, E560, MX470 and MX530