cubicweb #2742964 Adding postgres data type [in-progress]

It should be interresting to allow user to add specific postgres type (e.g. postigs/array) in their cubes.

prioritynormal
typeenhancement
done in<not specified>
load10.000
load left0.000
closed by<not specified>
patch[source] Now, possibly unprotect attributes can be pushed in the SQL INSERT query, e.g. for Postgis geometry records [applied]