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).

and prettier (to be used by update operations).

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

Disable cn=Schema "merging" messages

extensions field in the contained structures.

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)

Parsing and printing of extensions in schema definitions.