Change the mode of pid file for snmpd from 0600 to 0644

References:
 https://bugs.debian.org/528103

For systemd units, logging is set to warning on stdout. This means
systemd journald will capture the logs like other daemons.

Removed the file to /dev/null because it looks like there is no default
logfile.

Removed options on the configure line that are already the defaults.

libsnmp soname moved from 30 to 35

Closes: #917444

The default loggin of -Lsd is far too verbose. This change settles
it down by logging warning and above by default.

Closes: #792623

As oldstable uses snmp 5.7.2.1 removing all the old breaks and depends
on versions of the packages that just shouldn't exist anymore.

libsnmp15 and libsnmp9 are pre-jessie so they are gone too

Debian standards to 4.3.0
debhelper compat to 12

Update/remove the patches due to the new upstream source

Update to upstream version '5.8+dfsg'
with Debian dir c9611dcad5841ccc8f65458db91edaa8cd90782c

The copyright and watch files needed some tweaking to automatically
download and repack upstreams tarball.

Apparently Files-Excluded has a very limited glob function :(

Upstream version 5.8

Replace /usr/bin/env perl with /usr/bin/perl to follow Debian
policy

MariaDB 10.2+ API changed

References:
 https://sourceforge.net/p/net-snmp/bugs/2782/

If a system has libsnmp installed but not snmp cli installed, then the
snmp.conf file is missing and anything using the library may get a flood
of error messages.

The configuration file is not a /usr/bin/snmp configuration file, but a
configuration file for the library as there may be things that use the
library outside the snmp package.

References:
 https://bugs.debian.org/914657

Instead of badly guessing the upstream version, use dh_makeshlibs decide
what this is.

References:
 https://bugs.debian.org/912685

snmpd used to remove the Debian-snmp user every upgrade. It will
only now happen if you purge the package.

The problem is if the system users move around, then the uid changes
making some auditing programs complain.

Closes: #911216

Gbp-Dch: Ignore

Closes: #910638

Gbp-Dch: Ignore

debian/copyright now using the standard formatting. Due to the
upstream copyright files having their own errors and omissions
these may have been copied across, but I've done some level of
checking.

Closes: #898197

During a parallel build the perl module is made without linking
to the non-completed library which makes a useless perl module.

This minor change to the Makefile means the perl module is made
after the library is made.

Closes: #894626
Thanks to Gregor Herrmann for the patch.