Streamie 4+

Full release notes are here: https://help.streamieapp.com/a/ha_tOGa5DwkdG

- Updates some of the various StreamingSession-related classes to not use DispatchQueue.global() (which I need to be more consistent with; it's just so handy sometimes), because it'll get "clogged up" and then everything stops working.
- Adds keyboard command support for controlling pan, tilt and zoom on iOS (and macOS). To pan / tilt use the arrow keys. To zoom, use the up / down arrow keys with the shift key.
- Updates the "downgrade an account" server code, specifically with regards to handling excess account members, to reference the "last seen" history and choose the least recently seen account members for removal from the account. I also updated the old school "unlimited_cameras" purchases to support up to five account members (instead of one). I figure that if you've been using Streamie for 3+ years, your continued use is appreciated.
- Fixes an issue where if you tap on a shared camera link, that shared camera would not automatically be added to your cameras list if you were not allowed to add additional cameras. This is incorrect behavior because shared cameras (much like attached cameras) don't count against your account camera limits, while Nest, ONVIF, RTSP, UniFi cameras _do_ count against your account camera limits. [TM]
- Adds on-device Markdown rendering support for in-line code (denoted with back-ticks). There was existing support for whole lines/paragraphs, but not for substrings in a line. Support for both forms was already in place for the Markdown HTML renderer.
- Adjusts the CMCKrillClient presentation-times-have-rolled-over limits from 4B to 2B, with the expectation that maybe some cameras do 2^31 instead of 2^32?
- Fixes an issue in CMCKrillStreamingSession where if a reconnect occurs and the presentation times roll over, while we were correctly handling that situation for video, we had not duplicated that code for audio. Fixed.
- The default support ticket message when I'm communicating with a user now includes our toll free phone number.
- Adds support for encrypting Event thumbnails, snapshots and recordings. This task was deferred previously due to challenges in loading the thumbnail in the notification service (which shows you the push notification with an image).
- Overhauls the file upload mechanism. You don't care about the details for this one.
- Fixes an issue where nothing would ever happen if you tried to start multiple remote streams at the same time.
- Fixes an expired access token issue with YouTube Live Streaming where it was not automatically refreshed.
- Fixes another ONVIF WSSE authentication issue that can occur when a certain Lorex NVR miscalculates GMT. [CB]
- Overhauls the camera recorder (Record to NAS). You should see considerably faster loading times with all new recordings.
- Fixes a YouTube Live Streaming issue where a seemingly random, no obvious cause, failure of either of the AVAssetWriters (one for audio, one for video) would cause the live stream to fail (obviously). The movie writer will now reset and recover from the error. It'll signal the YouTubeService to reset the other writer. The stream recovers and all is well. You’ll have a “hiccup” in your live stream for like a minute or so.
- Improves remote streaming reliability. Specifically, on the client side, when a connection unexpectedly closes, the reconnection process should be more likely to succeed. One specific issue had to do with the data packet re-order queue. When a reconnect occurred, the server naturally started the sequence over at zero, while the client still expected data packets to continue in the sequence.
- Fixes another audio-related crash where I was improperly accessing unsafe memory. Sigh. I’m a little shocked this doesn’t cause frequent crashes.