[IMP] Speed and quality improvement   - removing the need of the use of search when groupby is set on a relation     field.   - creation and use of dedicated helper method to compute the orderby clause     for easier reading
[IMP] Speed and quality improvement
  - removing the need of the use of search when groupby is set on a relation
    field.
  - creation and use of dedicated helper method to compute the orderby clause
    for easier reading


akretion/openerp-server,akretion/openerp-server,akretion/openerp-server