20110902

Repairing iGen

lino.apps.igen was broken after docs/tickets/48. Started to repair it.

Added related_name to lino.mixins.AutoUser.user to avoid name clashes in lino.modlib.sales.models.SalesDocument

New function lino.tools.makedirs_if_missing().

Noted new ticket docs/tickets/49.

Check-in 20110902.

Solved some problems with docs.

Check-in 20110902b.