Zircon responds to various command line options and checks for various
environment variables. It also reads a preferences file which by
default lives in the file ~/.zircon/preferences (where ~ is your home
directory). Future versions of zircon will use the .zircon directory
for storing other configuration files etc. Environment variables have
take precedence over values set in the configuration file, and values
set on the command line take precedence over environment
variables. Before doing any of these, zircon will attempt to read the
system preferences file if it exists.

The command line options are :

	-j	: do *not* join channels that have auto-join set on them.
	-o	: do not process on conditions
	-z	: do not read *any* preferences files.
	-r	: the name of a preferences file to read. The system
		  file will *not* be read in this case.
	-i	: set your ircname
	-N	: set the nickname to use
	-S	: set the host name of the server to use
	-d	: set the name of the directory where the preferences
		  file lives.
	-C	: starts zircon without connecting to a server
