Fetch partition directly from self, by using UnrestrictedMethod, and use later
_assertACI in order to check permission.

Rationale: unrestrictedSearchResults will return all partitions, when Software
Instance needs access to only one.

Also change behavior to ignore cases defined in e93f690.

1/ Partition without SR is ignored.
2/ Partition that are empty and already in destroyed state are ignored.

Access Contents Information is checked in order to avoid accessing unauthorised
objects.

This reverts commit c5409c67.

If it works well, all dead code will be cleaned in future versions of slapos.core

It will espace transaction boundaries, so minimise calling needless methods.

Additionaly there is higher chance to have objects reindexed this way.

Whenever planned Sale Order is reindexed try to fire up ordering alarm.
Whenever ordered Sale Order is reindexed try to fire up confirming alarm.
Whenever Hosting Subscription is reindexed try to fire up update open order alarm.
In all cases obey alarm configuration (if it is subscribed, if alarm is active,
if is not running).

Whenever item is reindexed (Software Instance, Slave Instance, Software
Installation or Computer Partition) try to register recalculation of related
computer cache.

In neither case try to be "smart" (eg. waiting for reindexation to finish) as
this code just tries to speed up the system, it cannot achieve synchronism of
updates.

This reverts commit e96ef577.