Allow case-insensitive host/service match

[ssaxnagios]

Currently Nagios is case-sensitive for both the host/service names when submitting results. It would be nice to have a case-insensitive lookup on these when submitting passives/etc.

For example, if I submit something with LOCALHOST it won't match localhost.

If that option is enabled though then it would also need to make sure it isn't possible to have multiple with different case.

Requested here:

https://support.nagios.com/forum/viewtopic.php?t=61875#326812

[ericloyd]

As the request was from me in the first place, I'd like to clarify that I'm only looking for hostnames to be case insensitive. Service names can stay sensitive, but RFC (https://tools.ietf.org/html/rfc4343 states that FQDNs are not sensitive.