advapi32: partial LookupAccountSid implementation

[Robert Reif]

Robert Reif wrote:

> Implement some more of LookupAccountSidW for local computer.
> Make LookupAccountSidA use LookupAccountSidW.
> Add debugstr_sid for local debugging.

Please hold off on this patch.  It seems to have a problem. 

It passed the windows compiled tests but I am seeing a problem
with the tests when ported to the wine tests framework.