Add iSwiff cask

iSwiff is SWF Player.
Add Google Nik Collection
Add TextSoap.app
Upgrade x2goclient to latest
Delete special files (eg symlinks) from pkg BOMs

`pkgutil --only-files` plus `pkgutil --only-dirs` does not
cover all files in the BOM.

Closes #5491
Add Sony Homestream v1.1 cask
sha256 is :no_check, version is 'latest'
Add Beatport Pro v2.5.0
Add Rekordbox v3.0.0
audio-mate 2.0.4
Merge pull request #5567 from chulkilee/audio-mate-2.0.4

audio-mate 2.0.4
Merge pull request #5565 from dziemba/beatport-pro

Add Beatport Pro v2.5.0
Beatport Pro: Make easier to update
Merge pull request #5568 from nanoxd/master

Beatport Pro: Make easier to update
Merge pull request #5556 from fapper/homestream

Add Sony Homestream v1.1 cask
Merge pull request #5551 from mtneug/x2goclient

Upgrade x2goclient to latest
Merge pull request #5550 from lucashorton/textsoap

Add TextSoap.app
Merge pull request #5549 from lucashorton/google-nik-collection

Add Google Nik Collection
Merge pull request #5537 from joker1007/add_iswiff

Add iSwiff cask
Merge pull request #5566 from dziemba/rekordbox

Add Rekordbox v3.0.0