check_swap - fix comment

Signed-off-by: Davide Madrisan <davide.madrisan@gmail.com>
Improving output when swap space has zero size
Remove LEGAL file
Fix perfdata to comply with perfdata UOM definition
NEWS: Add warning regarding check_mrtgtraf change

Closes #1296.
check_snmp: Add thresholds to performance data
NEWS: Mention check_snmp's perfdata thresholds
Introduce support for SNMPv3 context in check_snmp

snmpget already supports using SNMPv3 contexts using the option "-n".
Thus all we need to do is introduce a new argument to check_snmp and
pass the argument on to snmpget using snmpget's option "-n".
Since "-n" is already in use for check_snmp for a different purpose,
we use "-N" instead.
NEWS: Mention new check_snmp option

Closes #1221.
Added perfdata to check_nt. New -l options - seconds|minutes|hours|days.
NEWS: Mention new "check_nt -l" parameters

Closes #1253.
check_ssh: change warning to critical for protocal/version errors

It makes more sense to exit critical if a explicit version/protocol is requested. This
would also be more consistent with other plugins. Other string matching plugins like
check_snmp or check_http exit critical if the result does not match.

Signed-off-by: Sven Nierlein <sven@nierlein.de>

Closes #1268
Adding a warning for raising to CRITICAL for protocal/version errors of check_ssh
avoid a segfault, if ulimit is set to unlimited
make constants from maxfd values (#1300)

its good practice to use constants instead of (random) values.

Signed-off-by: Sven Nierlein <sven@nierlein.de>
Merge pull request #1304 from monitoring-plugins/pr-1183-enhanced

merge pull request #1300 while moving values to constants
Use kernel reception time on ICMP packets to compute rtt.

This commit uses the SO_TIMESTAMP feature of setsockopt to fetch
kernel reception time of ICMP packets. This avoids invalid
computations of rtt on machines with heavy load and/or heavy
network traffic.
Don't mix variable declarations and code

We still support pre-C99 compilers.
check_icmp: Fix a few type errors
Added missing CR in DESCRIBE request.