Add nagios-plugins.spec file to .gitignore

The nagios-plugins.spec file is created from nagios-plugins.spec.in and
should be ignored by Git.
Disable stateless SSL session resumption

Some versions of OpenSSL fail to negotiate the SSL connection with at
least some versions of Tomcat if stateless SSL session resumption
support (see RFC4507) is enabled:

| CRITICAL - Cannot make SSL connection
| 140099330348712:error:140943F2:SSL routines:SSL3_READ_BYTES:sslv3 alert unexpected message:s3_pkt.c:1195:SSL alert number 10

The problem is reproducible with OpenSSL 1.0.0h, but not with OpenSSL
0.9.8o-4squeeze12 (as shipped with Debian 6.0.4).  We work around it by
disabling the RFC4507 functionality when using OpenSSL versions which
support it.

Thanks to Dag Bakke for reporting the issue and for giving me access to
a server I could use to reproduce the problem.
Add support for specifying SSL protocol version

The check_http -S/--ssl option now takes an optional argument which
specifies the desired SSL/TLS protocol version (#3285367 - Jason Lunn).
check_http: Don't ignore SSL initialization errors

SSL initialization errors are now handled properly by check_http
(#3095106 - Eric Schoeller).
check_http: Fix -C/--certificate option handling

The support for specifying the desired SSL protocol version via an
optional -S/--ssl argument broke the -C/--certificate option.  This is
fixed now.
Added check_range shell function to utils.sh.in
Mention the check_range function in NEWS, etc.
sslutils: Check if OpenSSL supports SSLv2.

Recent versions/builds seem to disable that feature.
Initial version of the 'check_dbi' plugin.

This plugin connects to an SQL database using libdbi, thus supporting all
database backends supported by libdbi. It will then issue the specified SQL
query and check the result (the numeric value of the first column of the first
row to be precise) against the specified warning/critical ranges.

The performance data includes the connection time (µs-resolution as provided
by gettimeofday()) and the query result.
check_dbi: Include extra opts in help output.
check_dbi: Added threshold ranges for the connection time.

The -W and -C options are used for that. The plugin return value is determined
by the worst check result.
check_dbi: Check and report the time used by the query.
check_dbi: Fixed/improved perfdata output.

 - do not use zero as 'min' value for the query result perfdata

 - added all semicolons
check_dbi: Replaced -W/-C with -m.

The -m option may be used to specify a metric to check the thresholds against.
This is more flexible than --conntime-warning/--conntime-critical (-W/-C) as
it may be extended to support further metrics without introducing tons of
arguments. Also, it does not make much sense to check the conntime and query
result at the same time.

Currently, the metrics CONN_TIME and QUERY_RESULT are available.

A query is no longer required unless QUERY_RESULT (the default) is used.
check_dbi: Added QUERY_TIME metric.

This metric checks the execution time of the specified query. In case the
query does not return any (parsable) data, this is not treated as an error
when using this metric.
check_dbi: Added some examples to the help output.
check_dbi: Added -e option.

This option may be used to specify a string that is expected as the query
return value. The string is compared to the query result using strcmp().

The option may not be mixed with -w/-c.
check_dbi: Added -r and -R options.

These options may be used to specify an extended POSIX regular expression that
is applied to the query result. When using -R, a case-insensitive match is
done.

The options may not be mixed with -w/-c/-e.
check_dbi: Added SERVER_VERSION metric.

This metric compares the database engine server version with the specified
ranges. The version string [[[[A.]B.]C.]D.]E[.] is returned as E + D*100 +
C*10000 + B*1000000 + A*100000000 (see libdbi's dbi_conn_get_engine_version()
documentation).
check_dbi: Added simple regex example to help output.