cubicweb-preview #3216722 Factor out a preview controller mixin to help writing a custom one [resolved]

The preview trampoline code is of general interest, including for custom controllers, and should thus be factored out.

prioritynormal
typeenhancement
done in1.1.0
load0.100
load left0.000
closed by#38b5260fbd2f Factor out a preview controller mixin to benefit from the javascript code
patchFactor out a preview controller mixin to benefit from the javascript code [applied]