Use json11 instead.

Replace it with the typical strerror for platforms that dont have full
posix support (freebsd/clang).

fixes #3835

When /bin/sh isn't bash, the previous line always appears to succeed,
and modinfo's output is not redirected, because it actually runs
modinfo in the background (which always succeeds) then opens and closes
/dev/null without doing anything to it. This causes us to always think
that the v4l2loopback module is installed, even when it isn't.

Fixes an issue where the hotkey entries would be duplicated
(including in the UI hotkey list) on every Profile switch.

This matches the behaviour of Scenes and the Audio Mixer.

Gives the MachServer a unique name which was forgotten in a previous commit

The vod track in advanced output mode would be overwritten by twitch
soundtrack's vod track. Additionally, simple output mode would overwrite
twitch's soundtrack vod track even when vod track was turned off in
settings.

So instead, if vod track is off, don't clear the secondary encoder
unless it's explicitly our encoder. Additionally, make sure that
advanced output mode's vod track encoder behaves consistently with
simple output mode's vod track so it doesn't get overwritten.

Was meant to be "adv" meaning advanced rather than "avc"

Similar to 315fbd6f and 6071098a, ignore non-fatal errors during the
remux process. It's possible OBS itself writes a file that generates
these errors when remuxed.

Previously sliders would not be disabled when the the obs_property was
disabled.

UI: fix typo

This setting, although technically different from the one in the
streaming section of settings, is superseded by that setting.

The setting can still be used via ini file if an actual custom rate
control or keyframe interval is needed.

Also updates references from 2017 to 2019 for consistency.

UI: Use Qt::MiddleButton instead of deprecated Qt::MidButton

- Log CEF version
- Add internal support for CEF 4183
- Add support for CMake 3.19.0
- Add support for fractional scaling in browser panels

This fixes an issue on Windows where loading on a
150% scale display renders OBS windows at 200%.

Reference: https://doc.qt.io/qt-5/qguiapplication.html#setHighDpiScaleFactorRoundingPolicy

CI: Add decklink-captions to dylibbundler fixups

The Scene Collection Importer would attempt to set the new filename
using the name property of the scene collection. However, it would
determine an unused filename, and then replace spaces with underscores,
which could cause a name collision. This changes the importer to replace
spaces with underscores first for the base filename, and then determine
an unused filename.

This commit fixes various issues with screen readers in the main OBS
interface. These were tested using NVDA on Windows 10 2004.

Audio track selection in Settings now says Track 1, 2, etc, rather than
just the number.

Various checkboxes that just say "Enable" now have accessible text that
says what the enable is for (since it says "checkbox", the fact it's an
enable should hopefully be clear).

Type in the recording tab of output now has accessible text which says
"Recording Type".

Items in the Advanced Audio Properties window now have accessible text
for what they are for. Currently some do not report correct values, but
that will require an accessible interface in Qt to be written
specifically for that, which will be done at a later date.

Buttons in the filters window now have accessible text for what they do.

All the right side buttons in hotkeys now have tooltips, and by
extension, accessible text.

This can be useful for reading from textures provided by middleware.