[server/session] add missing rollback when freeing a db connection When we let go of a cnxset and give it back to the pool, we need to make sure it's not in the middle of a transaction. We got bitten by a migration where the connection used by admin's repo.connect was not rolled back before attempting the migration, causing a deadlock because it had a lock on a table. This could potentially also be an issue for e.g. hooks or looping tasks that didn't explicitly rollback before calling free_cnxset or moving out of a ensure_cnx_set block.

action box
    Area visible in the upper left column. You have a list of available actions on the entity. The most frequently used entry is `modify`.

object
    All element created in the application
    Example: project, ticket, user, ...

relation editing module
    HTML widget that let you define new relations amongst objects.

relation
    It's a kind of 'smart' link between 2 objets of the application. It has a specific sense that determine dynamic behaviour and add a new logic of the content.