[vreg] move base registry implementation to logilab.common. Closes #1916014
A new logilab.common.registry module has been created with content from
* cw.vreg (the whole things that was in there)
* cw.appobject (base selectors and all).
In the process, we've done some renaming:
* former selector functions are now known as "predicate", though you still
use predicates to build an object'selector
* hence `objectify_selector` decorator is now `objectify_predicate`
* the top level registry is now `RegistryStore` (was `VRegistry`)
Also there is no more need for the @lltrace decorator.
On the CubicWeb side, the `selectors` module has been renamed to `predicates`.
There should be full backward compat with proper deprecation warnings.
<?xml version="1.0" encoding="UTF-8"?>
<display window-flags="sticky, below" width="185" height="200">
<sensor id="r" module="rqlsensor"/>
<sensor id="FS" module="FontSelector,1,Sans 10 black"/>
<!-- left border -->
<group x="0" width="5" height="200" bg-uri="gfx/border-left.png"/>
<image x="10" y="0" uri="gfx/logo_erudi.png"/>
<array id="results" x="10" y="30"
watch="layout=r:layout, length=r:length">
<label id="lbls1" color="black"
on-enter="r:enter-line"
on-leave="r:leave-line"
on-click="r:click-line"
watch="value=r:result, font=FS:font0, color=r:resultbg"/>
</array>
</display>