[SSSD] [PATCHES] Add backend part of user views

[Sumit Bose]

Hi,

this patches contain the IPA provider part of
https://fedorahosted.org/sssd/ticket/2375  as described in the FreeIPA
design page
http://www.freeipa.org/page/V4/Migrating_existing_environments_to_Trust

Patches 0001, 0006 and 0007 contain new sysdb interfaces for views and
overrides. 0002 and 0003 refactor some already existing calls.

0004 adds the initial support for views and overrides and reads the view
name for the client from the FreeIPA server or sets it to 'default' when
running in ipa-server-mode. It adds some new options which currently
misses man page entries and are not added to the python config API. I
did this on purpose for the time being because I wanted to see first if
the list is complete or if some options ca be dropped.

0005 adds the request to get a specific override from the FreeIPA server
and finally in 0008 the overrides are read during a request and saves or
applied.

This patches must be applied on to of the extdom patch I send yesterday.
To add and manage views and override on the server side please have a
look at Tomas's patch set on the freeipa-devel list
(https://www.redhat.com/archives/freeipa-devel/2014-September/msg00336.html).

bye,
Sumit