Now "make uninstall" removes the installed "ngircd.conf" file, if it
is still equal to our "sample-ngircd.conf" file and therefore hasn't
been modified by the user. If it has been modified, it isn't removed
and a notice is displayed to the user.
In addition, "make install" now displays a message when no ngircd.conf
file exists and the "sample-ngircd.conf" file will be installed as a
starting point.