[FIX] orm.copy_data: avoid reading useless and possibly expensive data when copying records
  
Rather than reading the data and discarding it,
it is much faster to not read it in the first place.
Launchpad automatic translations update.
[FIX] project.task: simplify delegated tasks remapping after task copy + avoid write() call if not necessary

This avoids recomputing function fields if not
necessary.
[FIX] project.copy(): avoid preparing useless children data to copy, as they are discared in analytic.copy. Duplicating children is handled by  duplicate_template().
[FIX] mail.thread: avoid tracking multiple temporary changes during copy
Merge branch 'openobject-server/7.0' into demo/7.0
Merge branch 'openobject-addons/7.0' into demo/7.0