Assert copyright.

src/syncterm/ssh.c

src/syncterm/ssh.h

src/syncterm/st_crypt.c

src/syncterm/st_crypt.h

src/syncterm/syncterm.c

src/syncterm/syncterm.h

src/syncterm/telnet_io.c

src/syncterm/telnet_io.h

src/syncterm/term.c

src/syncterm/term.h

src/syncterm/uifcinit.c

src/syncterm/uifcinit.h

src/syncterm/window.c

src/syncterm/window.h