Depreciate -D option (-D now gives a depreciation warning) and removed from

the help.

Depreciate two-char -i option (-i now gives a depreciation warning) and
removed from the help.

Expand the -i option to specify the desired interface... X, Curses, Curses
with forced IBM charset, Win32, or ANSI... if anything else is chosen, display
help (My first valid use of a goto in Synchronet code!  Whee!)