- move prompt for password to imap_open()
- don't ask for global password in PREAUTH state
- use socketpair() to create one full-duplex fd in tunnel mode
instead of two half-duplex pipes
- don't set lck.l_pid in fcntl() call (its read-only)
- use F_SETLK instead of F_SETLKW to avoid infinite waiting
- use "$@" in autogen.sh to get proper word expansion
move dotlocking code to dotlock.c.
dotlocking code fixed to ignore whether or not the lockfile exists on
open(). we only care about whether fcntl() was able to lock it.
