A first stab at reading the Nsca daemon

I'd rather see this as a second fifo in nagios-receiver that has
a select() loop around the 2 filedescriptors, then sending
the line to a specialized parser method.

Awaiting any comments
minor cleanups
A few stylistic changes

As per Ali's suggestions
Merge pull request #444 from giganteous/nsca-receiver

A first stab at reading the Nsca daemon