Add better approx test

consolidated into the Operation structure. All reply parameters
are consolidated into the new SlapReply structure. Most operations
now have identical call signatures... Changes are not #ifdef'd,
revert to -r NO_SLAP_OP_BLOCKS if necessary to back out.

no normalizer, a_nvals = a_vals.

	schema engine updated (but not schema routines so things don't run yet)
	nvalues mostly populated, enough for tests 0-2 to pass
	schema routines needs lots of work
	modify/mods codes needs lots of work

of rule uses, but also in test_filter_mra()

  to back-bdb, back-ldbm and back-sql (the latter with limitations);
- added handling of ":dn" attributes to extended rfc2254 filters
  and to matched value filter
- altered the behavior of get_mra() when a matching rule is given:
  now it checks whether it is compatible with the attribute syntax
  and, in case it is, the given mr is used.  In case of no type,
  the check is delayed when filtering

Coverted LDAP_LOG macro to use subsystem ID int values instead of string values

extensible matching

new extensible matching rules.

value-independent access controls.

	SLAP_MR_ASSERTION_SYNTAX_MATCH
	SLAP_MR_VALUE_SYNTAX_MATCH
	SLAP_MR_VALUE_SYNTAX_CONVERTED_MATCH,
add supporting evaluation macros, and update code as needed.
Misc other code cleanup included.

values as stored in the entry on the one hand and an assertion value
that is not necessarily of the same syntax.  So tell value_match this
is the case by setting SLAP_MR_VALUE_IS_IN_MR_SYNTAX in flags.

and integerBitOrMatch enhancement (ITS#1302 + minor changes)
from Luke Howard <lukeh@padl.com>.