[selectors] move lltrace decorator and traced_selection cm to appobject module so we can apply lltrace to And/Or/Not selectors, fixing #662565

with cw 3.9, no more Image type

[vreg] on registration completed, don't crash if an object depends on an unexistant registry, simply kick the object out

[selectors] ensure adaptable('IDownloadable') takes precedence over implements('Any')

[primary view] fix name error on dispctrl w/ pre 3.5 box definition

[entity] fix access to attribute which has been renamed two revisions ago

[schema migration] make some stuff to ease file 1.9 migration : we want to kill the Image entity so that existing image are turned into (existing entity type) File entities

[entity] continue cleanup of Entity/AnyEntity namespace * prefix by cw_ or _cw all '2nd zone' attributes / methods, other most commonly used will be done later (some methods used by client are made private anyway when they are for internal purpose anyway) * kill set_eid, use direct affectation instead * kill the auto-transmutation feature (pre_add_hook), hence releasing 3.9 will require releasing file cube as well

[entity] introduce a new 'adapters' registry This changeset introduces the notion in adapters (as in Zope Component Architecture) in a cubicweb way, eg using a specific registry of appobjects. This allows nicer code structure, by avoid clutering entity classes and moving code usually specific to a place of the ui (or something else) together with the code that use the interface. We don't use actual interface anymore, they are implied by adapters (which may be abstract), whose reg id is an interface name. Appobjects that used to 'implements(IFace)' should now be rewritten by: * coding an IFaceAdapter(EntityAdapter) defining (implementing if desired) the interface, usually with __regid__ = 'IFace' * use "adaptable('IFace')" as selector instead Also, the implements_adapter_compat decorator eases backward compatibility with adapter's methods that may still be found on entities implementing the interface. Notice that unlike ZCA, we don't support automatic adapters chain (yagni?). All interfaces defined in cubicweb have been turned into adapters, also some new ones have been introduced to cleanup Entity / AnyEntity classes namespace. At the end, the pluggable mixins mecanism should disappear in favor of adapters as well.

backport stable