ldb dn tests

[Matthias Dieter Wallnöfer]

Andrew Bartlett wrote:
> C-based ldb DN tests can be added to the existing DN tests in
> torture/ldb/ldb.c.  (There is a function there for normal DNs, alongside
> the extended DN tests).
>
> These should be extended to include testing these cases, alongside
> adding the shell-based tests that have been mentioned (which are part of
> the official LDB distribution).
>    
I will add a small test for a comma-separated DN since the real crash 
test has already been added to "sam.py".

Matthias