[Patch] Row level security support

Hello,

 

I've implemented basic support for Row-level security policies (introduced in PostgreSQL 9.5) in PgAdmin3. Please, have a look at patches attached to mail.

 

First patch contains pgPolicy tree object, dlgPolicy dialog, some small changes in the pgTable and dlgTable code to represent new security options (ENABLE/FORCE RLS).

 

Second patch implements tab-completion for new statements (CREATE/ALTER/DROP POLICY).

I've decided to put these into separate patch, because I don't know whether I've done it correctly: seems like tab-complete.inc used to be generated by tabcomplete.pl once,
but it doesn't look like a viable option anymore (script failed at first match with latest tab-complete.c from psql repository). So I've just edited tab-complete.inc manually. 

Best Regards,
Alexander