Instances with subscription request can also request Slave Instances for frontends and others on shared computers.

This allow configure more precisely the Capacity Quantity for an instance based on its software type.

It's not needed to show destroyed Software Installation in "Supplied Softwares" list which only make the research more harder.

assertEquals is deprecated, see https://docs.python.org/2.7/library/unittest.html#deprecated-aliases

/reviewed-on !58

`Catalog query with  query_kw["allocation_scope_uid"] = NegatedQuery(SimpleQuery(UID))` is ignored in the query. We can set the list of accepted UID in the query instead.

/reviewed-on !57

Individual variation can define pricing and capacity consumption per software type.

Prioritize computer_guid for now while parent_reference is used.

slapos_erp5: Since capacity scope is updated after allocation, the computer should have access on mememcached

For prevent over allocation, we have to update the state of the Computer just after the allocation. This don't replace alarms to control the global state (when capacity is updated etc etc)

It was set to output on stderr, which is not natural and inconvenient

  Those files are created when eggs are generated, so ignore them.

slapos_erp5: Computers with subscription allocation scope has same security as the ones with open allocation

Use sticky-computer to make the requester use same COMP reference when request himself. It allow us to maintain the requested instance on the same computer as the requester.

Based on allocation scope computers can be segmented for subscribers type, and project_guid can
be used to limit the targeting case.

This category, when set on a computer, defines is as Open for Allocation, but only Subscribers can allocate. Normally, only instances that are linked to a Subscription Request.