Add more command-line arguments to the Nagios CollecTor check script

Moved here from legacy/trac#33972 (moved):

I'll also look into the parameters and using argparse next week. Unfortunately, the check wouldn't work for corsicum right now anyway, because that CollecTor instance does not archive all descriptor types. It would just keep shouting about timestamps being missing. Maybe we'll need to add another option to only complain about outdated timestamp, not about missing timestamps. Added to my list.

These are two changes:

• add two separate host and IP parameters as suggested on the other ticket and
• add another parameter for ignoring missing timestamps.

None of these changes are critical, but making them sooner rather than later reduces the overhead for context switching.

The check script is here.