1.5.4: Minor bug fix release

1.5.4 is now available for automatic update. This is another minor bug release, see the full changelog below:

* Add – Notice if a package does not have any products assigned to it
* Fix – Users with apostrophe in their name broke Private Gallery user selection
* Fix – Bulk add products didn’t assign categories properly
* Fix – Netherlands translation
* Fix – If invalid login, lost Sunshine login screen and got default WordPress screen