Added support for providing a custom params dict
Added support for providing a custom params dict

This has been a long outstanding feature request for tlarsen, luckily
it turned out to be very easy to implement with the dict.merge
utility method. To have custom _rights one should instead to the
required access checks before calling the view method.

--HG--
extra : convert_revision : svn%3A32761e7d-7263-4528-b7be-7235b26367ec/trunk%40999

SRabbelier/Melange,SRabbelier/Melange,SRabbelier/Melange,SRabbelier/Melange,SRabbelier/Melange,SRabbelier/Melange,SRabbelier/Melange,SRabbelier/Melange,SRabbelier/Melange