Add warning to rc script of files not included by default newsyslog.conf
After the changes to the default /etc/newsyslog.conf made in rS340318,
if files in /etc/newsyslog.conf.d/ or /usr/local/etc/newsyslog.conf.d/
start with '.' or do not end with '.conf' then print a warning at boot
time to notify the user they are not included in the default
Exclude files ending in '.sample|.bak|.orig|.rej' as it is unlikely they
were intended to be included by /etc/newsyslog.conf.
It is intended that this boot time warning is in addition to an entry in
/usr/src/UPDATING and also an entry in the release notes.