Fix log messages with the word second(s)
Do less work and more error checking in handle_events()

Added error checking to poll() in handle_events(). If there was an issue
that is not from a SIGNAL than it should be logged and NSCA should exit
in a critical state.

Also, only loop through each of the file descriptors if poll() found there
to be new data.
Fix style of some comments
Add error checking to fcntl()

Added error checking to fcntl() call that gets made only when running
in multi process daemon mode.
Fix some log messages
Remove unnecessary parenthesis in handle_events()
Fixes to smaller packet size logic

It seems that in 3950d852 some logic was added to make it so older clients
that use a smaller packet size could still communicate with newer servers.
While I think this is a good thing I'm not sure that the logic was added
in the right place. It was getting done inside an if statement used to
handle issues with recv() which doesn't really make sense to me since
after doing this the handle_read_events() would just return.

Will need to do some testing with older clients to see if this breaks
and to see if this ever worked.
Fix error checking and exit codes

Added more concise error checking and proper return values to
handle_connection_read().
Better error logging for send() and recv() calls
Log timeout messages not in debug mode
Only forward alive connections to their handlers
Style fixes
Exit on socket accept failures

Socket accept failures should cause the daemon to exit regardless of
which mode it is running.
Only do fd cleanup when necessary