Fix check_mysql.c client options from file

If you don't specify a group or a file to read data from the plugin tries to read from several files that don't exist and no groups.
check_nt: add UPTIME to perfdata [sf#3434647]
Add Sam Kottler to the list of AUTHORS
Remove the suggestion to run check_apt with --verbose since it doesn't do anything
check_snmp: Handle SNMPv3 noAuthNoPriv properly

The SNMPv3 noAuthNoPriv security level, somewhat unintuitively, requires
a security name to be passed along together with the request. Check_snmp
previously did not do this, causing snmpget to throw an error:

"External command error: No log handling enabled - turning on stderr
logging
snmpget: No securityName specified"

This patch fixes the issue by always providing the security name when
noAuthNoPriv is specified.

See also:
https:://bugs.op5.com/view.php?id=8385.

Signed-off-by: Anton Lofgren <alofgren@op5.com>
Add missing file extensions for some of the plugins.
Make check_ping work on Windows.
Make check_users work on Windows.
Make check_disk work on Windows.
Fix compilation with GnuTLS

GnuTLS doesn't provide a SSL_CTX_check_private_key() function.

Closes #1254.
configure.ac: Remove unused code

We no longer set LIBGNUTLS_CONFIG, as GnuTLS no longer ships a
"libgnutls-config" tool.
tests: parts of the check_procs test only work when uid -2 exists

skip those tests if the uid does not exist

Signed-off-by: Sven Nierlein <Sven.Nierlein@consol.de>
tests: testCmd has own timeout which overwrites local one

so add configurable/optional timeout to testCmd.

Signed-off-by: Sven Nierlein <Sven.Nierlein@consol.de>
require at least HTTP::Daemon 6.01

since the test uses send_header from HTTP::Daemon::ClientConn which has been introduced in
HTTP::Daemon 6.01
tests: fping checks require being root or setuid root

on the fping binary. Check this before running the test.

Signed-off-by: Sven Nierlein <Sven.Nierlein@consol.de>
tests: check_proc tests fail if uid -2 does not map to nobody

so make sure our tests only run if -2 maps to nobody

Signed-off-by: Sven Nierlein <Sven.Nierlein@consol.de>
tests: freebsds snmpd does not use quotes

when returning syscontact. So make them optional since we want to test
check_snmp and not the snmpd.

Signed-off-by: Sven Nierlein <Sven.Nierlein@consol.de>
lib/parse_ini.[ch]: Simplify code

Rewrite the code that looks up the INI configuration file path (used by
the Extra-Opts feature) in order to improve readability.  The behaviour
should not have changed.
lib/parse_ini.c: Read "monitoring-plugins.ini"

Read "monitoring-plugins.ini" if that file exists, but fall back to
reading "plugins.ini" or "nagios-plugins.ini" for backward
compatibility.
lib/parse_ini.c: Read $MP_CONFIG_FILE

Read $MP_CONFIG_FILE if that variable is set in the environment.