This should probably be revisited if the preview can be rotated in 3D,
or someone comes up with a good 3D manipulation idea for the preview

If you have an item with width = 0 and height = 0 close to (0, 0)
clicking anywhere in the preview window would select them

The remuxer thread was only started if there was an actual remux job,
which resulted in the remuxer thread not being able to call the worker's
destructor (because it wasn't running)

OBS Sparkle feeds have two extensions to vanilla Sparkle feeds:
- There can be two kinds of items per feed: (zipped) .app and .mpkg
  via <ce:packageType>app|mpkg</ce:packageType> (default is mpkg)
- Feed items can be disabled via <ce:deployed>false</ce:deployed>; these
  items will not be considered for updates unless
  "[General] UpdateToUndeployed=1" is set the global config

Unlike other Sparkle implementations the FeedURL cannot be updated via user
preferences because we support multiple app packages with the same package
identifier but different FeedURL settings on the same machine

Typedef pointers are unsafe.  If you do:
typedef struct bla *bla_t;
then you cannot use it as a constant, such as: const bla_t, because
that constant will be to the pointer itself rather than to the
underlying data.  I admit this was a fundamental mistake that must
be corrected.

All typedefs that were pointer types will now have their pointers
removed from the type itself, and the pointers will be used when they
are actually used as variables/parameters/returns instead.

This does not break ABI though, which is pretty nice.

It's better to use VBR for local recordings, so this option should be
nice for people who want to do that.

I feel like people keep mistaking how x264 preset functions.  They often
associate it with their own CPU speed, and I feel the name does not help
with that issue.  I think it may be for the best to just take it out.
At best, it will keep people away from using it unless they know what
they're doing, and at worst, people at least won't be able to associate
it with their CPU as easily anymore.

Change checkbox with text "Advanced Encoder Settings" to "Use Advanced
Encoder Settings".  This way it will hint that the settings will be
disabled when unchecked.

QT fakes a mouse move when destructing which is
caught by our filter

Adds:
ENABLE_UI (on by default) which makes it so that the UI is required, and
will fail if a dependency is not found.  This is on by default because
most people are building it with the user interface, and we'll probably
get a lot of issue reports stating "why is there no executable?" if we
don't have this on by default.

DISABLE_UI which forces the UI off.

If neither are set, then the UI will only be built if the dependencies
for it are found, otherwise the UI will be be ignored.

This doesn't really have a purpose, and appears to cause issues for
faruton's plugin, so removing it for the time being.

Followup to d5643230, it apparently
still crashed (on slower machines?) when closing the properties window
via mouse (by clicking the X button)

Some devices burst their audio (such as when querying audio from
directshow), and the 250 millisecond threshold that sets the audio meter
back to muted status would erroneously cause the meter to appear bounce
back between muted and unmuted.  Instead, a one second test should be
sufficient time to prevent that from happening.