cubicweb #1056023 be able to specify the schema in which DB tables are created and used [done]

For the backends which support it, having some control over the DB Schema used to store the tables can be very useful. A typical case is when the user creating the tables is not the same one as the one making queries. On some rdbms (Oracle, SQLServer are in that case, not sure for PostgreSQL), the user has a default schema linked to his login, and will not be able to use objects outside that schema unless the schema is made explicit in the queries.

done in<not specified>
load left0.000
closed by<not specified>