dselect/baselist.cc: don't specify SA_INTERRUPT, since it's not portable and the...

dselect/baselist.cc: don't specify SA_INTERRUPT, since it's not portable and the default behaviour
main/enquiry.c: include sys/termios.h (needed on Solaris)
lib/lock.c: use EACCESS instead of EWOULDBLOCK
dselect/main.cc: fix help for -D
dselect/main.cc: try to lock admindir instead of using readwrite
dselect/method.cc: switch to using fcntl for lock since that is more portable, and revamp lockingcode to reduce code duplication