Now providing real security by protecting the socket and making client setgid.

- Also added 'install' and 'uninstall' targets to Makefile.
Reorganized: Moved most of the code into the daemon program.  Renamed programs.

- The client program is called "jobber".
- The daemon program is called "jobberd".
Added init.d file; improved logging from daemon; added sec-level scheduling.

- Various improvements/fixes.
- Added "--all-users" option to some commands.