Timeout state

    Added timeout_state syntax to the timeout opt (-t)

    A few functions from teh nagios-plugins project were pulled into
    check_nrpe.c to make use of the sytax changes I made to the
    nagios-plugins branch "timeout_state".
    (https://github.com/nagios-plugins/nagios-plugins/commits/timeout_state)

    This is an attempt to universalize the timeout syntax in the plugins and
    nrpe.

    The changes should be backwards compatible.

    New syntax for the timeout is:

    -t <interval>:<state>

    <interval> is a positive integer.
    <state> is case insensitive and one of:
    state name: ok/warning/critical/unknown
    state id: 0/1/2/3

    For example:

    -t 5:0              5 second timeout with state "ok"
    -t :warning         default timeout (10) with state "warning"
    -t 5                5 second timeout with default state "critical"

    Marked the unknown opt (-u) as DEPRECATED.

    Added usage information for the new syntax.