Kerberos detection of des_debug
	detection of resolv.h and arpa/nameserv.h
Updated affected codes.

check for alias problem
check for alias != entry
check for null entry in subsequent switch statement

okay to read and write LDBM specific fields (state, refcnt,
LRU.  The id field, though is read-only once set.
cache_find_entry_dn2id(), hence, does not require any entry locks.
cache_find_entry_id() must do a entry_rdwr_trylock() and back
off if busy.
Add new rdwr lock code with trylock() functionality.
Implement entry_rdwr_trylock().

frontend-backend interface.
Includes a number changes to share common routines between
database api types.

new frontend-backend interface.

frontend->backend interface.

frontend->backend interface.

LDAP_ALIAS_PROBLEM is now only used if the alias itself is mangled.

fixed deadlocks

ldbm_cache_fetch() codes.

Fix memory leaks

Update acconfig.h to use @TOP@ and @BOTTOM@ to rid ourselves of
the .top/.bot files.

idl_free() had insurance.

needs work.

autoconf/automake environment and should always use provided configure.

Fix idl_nextid not to skip an ID if ID not in list.
Both of these should not occur if used correctly, but cheap insurance
against incorrect usage is welcomed.