[MERGE] various: be fussy on report names

Report naming has been recently updated at commit efdb5373 . However
some people, same kind of people who cannot walk on two stone steps at
a time or have to put their pens parallel on their desktop, thought
another step could be done in order to have the same convention of naming
for every report. Convention for report naming is now "<report name> -
<object name>".

This commit also improves the RNG validation of report tag in order to
be able to directly put print_report_name into the report declaration
instead of having to define it in a separate ir.actions.report.xml node.

This merges remote-tracking branch 'dev/master-report-name-youpie'.