Various bug fixes for demoinfo

[JimmyWoodhouse]

This is not an issue itself, but thought I would post this. Unfortunately I am not well-versed enough in git to cherry-pick specific commits from this to PR into demoinfo, but I have various different bug fixes in the commit history of this repository (a fork of demoinfo):
https://github.com/JamesT-W/demoinfo/commits/master

However, the most recent bug fix made to demoinfo is actually in a different repository as the one above is no longer in use. All demoinfo changes I have made are in this repository too, however this one also contains commits that are not related to demoinfo.
The only commit specific to this repository is: source-engine-discord/SourceEngine.Demo@3d3bb57 which I would recommend demoinfo is updated with.

The commits I would recommend viewing at the very least are:
source-engine-discord/SourceEngine.Demo@3d3bb57
https://github.com/JamesT-W/demoinfo/commit/0764cffede4276843034d21002a752a84601281a
https://github.com/JamesT-W/demoinfo/commit/4486ed87328122cfa40999afec66f7c37441171f

Not all commits are useful to demoinfo, as some are specific to the project I have been working on, however there are other commits that implement new features that you might be interested in, so it's still worth looking through the commit history if you're interested. (One thing to note, hostage_follows event was added, however this event is only triggered in demos recorded by the user, not demos recorded by the server annoyingly).

Finally, thanks for such a great program. It has allowed us to parse thousands of demos, and helped the mapping community a bunch. If you're interested, here's some examples of the work we have produced from this:
https://www.tophattwaffle.com/demos/requested.php?demo=MCHtop10_de_mutiny
https://www.tophattwaffle.com/demos/index.php?demo=2020_01_04_lure_ultimate_53b06d74-beb1-4b2d-b7ad-1126eb080f33
Cheers!

Edit
This was originally pointing to a new repo, instead of my demoinfo fork, so this will now be easier to merge in any specific commits necessary that when I originally posted this.