s4: dSHeuristics syntax check

[Nadezhda Ivanova]

Hi Matthias and team,
I implemented checking of the restrictions on dSHeuristics attribute, as
described in MS-ADTS 7.1.1.2.4.1.2, because it is being used in the aclread
module, and we should probably start to actually pay attention to its
settings in other places as well, such as accepting userPassword attribute
ot accepting a password reset over non-secure connection. I put the check in
objectclass_attrs, as this is the place where we generally check attribute
syntax, but if you have any objections or suggestions let me know.
Here are the patches:
Tests:
http://gitweb.samba.org/?p=nivanova/samba.git;a=commit;h=9c5490c9298aa29d9deb76702f21dd8f0d5b9902
Implementation:
http://gitweb.samba.org/?p=nivanova/samba.git;a=commit;h=d274e17fba5b5d047904595ae505339b8bd1176f


Regards,
Nadya