For ITS#2482:
  added sl_is_mute flag to Listener - when set, the listener is ignored
  if accept() on a listener fails with EMFILE, set the sl_is_mute flag
  when removing a connection, if emfile != 0, look for a listener to unmute

  For ITS#2374:
  if global_idletimeout is set and there are active sessions, use a timeout
  on the select() to actively detect idle sessions.

add create/modify timestamp to all entries; use monitorTimestamp for start/current time; minor cleanup

doesn't yet use ctx malloc routines

as an iterator!

the entire attribute.

test_filter will never match them anyway.

arg to tool_entry_open comes too late for back-bdb to use.

-test017-syncreplication

Fix slapi_filter_dup() crasher.

Add slapi_x_filter_append(), as a replacement for slapi_filter_join() that
can create compound filters containing multiple filters. Will propose API
to Sun DS team; until then it should likely be marked LDAP_DEVEL (if SLAPI
is not entirely marked as such already).