- warning if no units present for times or byte sizes

- warning if no units present for times or byte sizes
- added defaults to all time_t's in cf.data.pre
- Fixed up connect callbacks to recognize COMM_DNS_ERR and !COMM_OK
- Set FTP_HTTP_HEADER_SENT for ftp
- Initialize neighbors_do_private_keys in globals.c
- Remove opt_no_ipcache
- removed redundant externs from squid.h
- changed more debug_trap's to assert's
- changed over-high-water-mark warning to only report once at
  each threshold