Use -DSLAPD_SCHEMA_COMPAT to use 1.x compatible schema (deprecated).

Add syntax normalizer, separate from matching rule normalizer.
with mr normalizer defaulting to syntax normalizer.  This allows
for more consistent handling of some syntaxes, such as directoryString
(where all matches should ignore leading, trailing, and other extra
spaces).

	(2.5.4.0=2.5.6.0) works!	ie: (objectclass=top)

Disable cn=Schema "merging" messages

SASL mech removed from backend bind callback (as SASL is managed by frontend)
Changes to some backends are untested (as I don't have all dependent
  software install)

to appropriate syntaxes.

	added new value_normalize() code
	need LDAPsyntaxes X- field support

Add needed syntaxes defs to schema_init.c

to caller (do_search) such that info can be used by other
operations (ie: do_compare).
SLAPD_SCHEMA_NOT_COMPAT: Add additional code to support filters (needs work)

Add schema_prep() call to main()
Similiar changes to slapcommon.c
Add schema_prep() impl to schema_init.c
Add slap_ad_entry and slap_ad_children globals.
Add "entry" and "children" to openldap.schema (this likely should
  be added to schema via code, not configuration)

plus these changes unhidden changes:
	remove now meaning --enable-discreteaci configure option
	fix ITS#451, slapd filters
	Add ber_bvecadd() to support above
	constify ldap_pvt_find_wildcard() and misc slapd routines
	renamed some slap.h macros
	likely broken something

Changes outside of #ifdef include three value filter processing.

additional schema items.

attributes of the syntax.  Such attribute values be transferred
using binary syntax unless ber2str/str2ber routines are provided.
Used in conjunction with ";binary" attribute description option
and/or the Binary syntax.

routines to separate file to keep schema.c of managable size.