introduced backend_private perms in lists #338
refactor wrong method name isPermissionSetted

Changed to Permission::isPermissionSet()
entering obj detail check if it's forbidden #338

add Permission::isForbidden() method to check if an object is forbidden for user
hide objects with private perms on ancestors #338

also optimized the query to execute only if needed
locale of new permission backend_private #338
Merge branch 'master' into issue/338-implement-private-publications
add unit test for Permission::isForbidden() #338
handle save object positions #338
exclude forbidden objects from dashboard #338
exclude forbidden objs from dashboard search #338
handle many backend_private perms on same obj #338
Merge branch 'issue/338-implement-private-publications'