Fixes an error and a warning when compiling with experimental shared
texture support.

If the scene item crop/filtering is updated, instead of
creating/destroying the item texture on the spot, update it in the
graphics thread to prevent potential race conditions (especially when
the crop function for example could be called from within
obs_scene_enum_items in some situations, which would lock the graphics
and scene mutexes in the wrong order).

Allows the use of alt-cropping on scene items that have bounding box
enabled.  The crop will simply apply to the source within the bounding
box rather than try to do anything fancy.  A simple solution to an
annoying problem.

Instead, just check to see whether array and num are valid, and if they
are not, safely return.

Allow multiple QSV encoders, usefull for live + recorded parallel
sessions.  The first QSV encoder will create a DirectX device and return
a handle / pointer.  Any additional QSV encoder will use that same
pointer to the DirectX device.  We keep track of the number of open
QSV encoders so that we wait to close the DirectX resources after all
encoders are closed.

Closes obsproject/obs-studio#1341

Update INSTALL

UI: Fix stream button checkable state

UI: Update Acri theme for disabled buttons

CI: Fix CEF Path on Package Build

CI: Update Sparkle default base_url

UI: Add missing OBS_FRONTEND_EVENT_TRANSITION_LIST_CHANGED

Closes obsproject/obs-studio#1347

rtmp-services: Add KakaoTV

rtmp-services: Update ingest list for GamePlank

Because sub-items of groups can no longer reroute their signals to the
parent scenes of groups, delegates removal handling to SourceTreeItem
instead of OBSBasic.

Allows copying and pasting of groups.  The user can fully duplicate the
group, or create a reference of the group.  The user cannot paste a
reference of the group if it already exists within the same scene
however.

(This commit also modifies UI)

Changes groups to their own independent type, "group".  This allows them
to be used like other regular types, and allows the ability to reference
groups in multiple scenes.  Before, a group would always be linked to
the scene it was in.  This made it cumbersome for users to modify groups
if they had a similar group in multiple scenes (they would have to
modify each group in each scene).  Making groups like other source types
makes more sense to solve this issue so they can be referenced in
multiple scenes at once.  This also removes a significant amount of
group-specific handling code required for implementing groups in the
front-end.

One limitation however: due to the way sub-items of groups are
seamlessly modifiable and sortable as part of the whole scene, the user
cannot have multiple references to the same group within one scene.

Allows using a different source type (I.E. "group" instead of "scene").

(This commit also modifies UI)

Removes obs_scene::group_sceneitem and replaces it with
obs_scene::is_group.  Changes a number of other functions related to
groups so that a group is not inherently tied to a specific scene, and
helps allow a single group to be referenced in multiple scenes if
desired.

Allows easily/safely appending all the values of one data array to
another.

This event is fired during Add/Delete operations but was missing on
renaming a transition.

(This commit also modifies deps/libcaption)

Closes obsproject/obs-studio#1354

Fix GCC 9 Warnings

vlc-video: Dlopen libvlccore.dylib on mac OS

rtmp-services: Adding Castr.io ingests to service list

As of version 3, libvlc on macOS is linked against libvlccore
differently. Previously libvlccore was referred to via the @loader_path
macro, now @rpath is used. As such, dlopen is no longer able to find
libvlccore. Explicitly load libvlccore so that the symbols that
libvlc needs can be found.

Tested against VLC versions 2.2.8 and 3.0.3.

This fixes the pkg build of obs-browser by properly copying CEF to
`OBS.app/Content/Frameworks/Chromium Embedded Framework.framework`,
rather than `OBS.app/Content/Frameworks`.

This function returns a char *, so it should not be const (the value is
set from a function which also returns a char *, so there is no real
reason for this to be const).

Removes a likely unintentional self-comparison.