Web: allow import of models with '_inherits'
When a model has its '_inherits' defined, the associated fields are always set to 'required'. These models cannot be imported in the web client 6.1 because the web client insists that these fields be present in the import file. See https://bugs.launchpad.net/bugs/930318.
This module makes the web client query the content of a model's '_inherits' so that it can exclude them from the required fields at import time.
Due to the applied method of 'monkey patching', the installation of this module on one database will affect all databases on the same OpenERP installation.
This bug does not affect OpenERP 7.0, in which the import function has been refactored.