Help eliminate resource leaks.

Maybe fixed insertion bug in Linux SCFG.

Added rules to build makehlp and scfghelp only when necessary.
makehelp now puts output files directly in $(EXEODIR) (no mv necessary).

Added uifc.h.

Created SCFGHELP target.
Fixec clean target for Win32 builds.
Updated comment header.

Added command-line options to: set rlogin to second username,
enable telnet debug output, disable QWK events, disable the POP3 server,
disable the SendMail thread, disabled hostname lookups, disable JavaScript,
and to use local timezone (instead of assuming GMT/UTC).
Changed command-line options: u to un to set effective username, nf to f- to
disable FTP server and nm to m- to disable mail server.
Multiple dashes in command-line args are now ignored (e.g. "--ns").

Added nonblocking property to set socket to non-blocking mode (untested).
Private structures are zeroed after allocation.

Changed reporting of execvp() failure from errormsg() to errorlog().