Fix for Bug 3140 - It is possible to email someone else's private list

Fix for Bug 3140 - It is possible to email someone else's private list

Adding check for ShelfPossibleAction("view") to make sure the logged
in user has permission to view the selected list when downloading
or emailing a list.

Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>
Signed-off-by: Ian Walls <ian.walls@bywatersolutions.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
(cherry picked from commit b65f6d0a99dc13e73aed5058a44a72895c829b32)

Signed-off-by: Chris Nighswonger <chris.nighswonger@gmail.com>