Value 7 was actually 5.1 surround mode, not 7.1.

There were cases where the channel format could be set to 7, which used
to be a valid format but now no longer is.  If that format is set, just
use SPEAKERS_7POINT1 instead.

Makes it a bit more clear this option shouldn't be used unless you're on
SLI/crossfire.

In the future, something should be put in to the program that detects
laptops and warns on how to set up their adapter for efficient capture.

Closes jp9000/obs-studio#1138

cmake: Add more LuaJIT lib names

Revert "CI: Add Python path for AppVeyor"

linux-pulseaudio: Default sample format float32le

This pull request changes the fallback sample format for pulse-audio
to from PA_SAMPLE_S16LE to PA_SAMPLE_FLOAT32LE.

The pulseaudio plugin can handle the following sample format:
* PA_SAMPlE_U8
* PA_SAMPLE_S16LE
* PA_SAMPLE_S32LE
* PA_SAMPLE_FLOAT32LE

When an audio device advertises itself as another format, the pulseaudio-plugin
will ask pulse audio to convert to the fallback sample format.

The fallback PA_SAMPLE_S16LE is not ideal when your audio interface advertises
as PA_SAMPLE_S24LE since the conversion will lose precision.
With PA_SAMPLE_FLOAT32LE there is no precision loss and it is also equals OBS's
internal format.

Makes building on Windows easier.

This is not necessary with the updated pre-built windows dependencies.
This reverts commit 516e9daa.

CI: Add Python path for AppVeyor

Fixes swig/python dependencies to search for the pre-compiled deps on
windows.

libobs: Fix pulseaudio monitor playback stuttering

UI: Rework volume-meters, adding more information

libobs: Fix for int-in-bool-context-warning

The 'bool private' variable was receiving either OBS_SCENE_DUP_PRIVATE_COPY or
OBS_SCENE_DUP_COPY hence always being true.

rtmp-services: Add Twitch Helsinki ingest

linux-v4l2: Add 4k and 21:9 resolutions

ui: Fix unsaved changes dialog showing twice

UI: Add Click capabilities and Multiple Layouts to Multiview

obs-ffmpeg: Fix ffmpeg output recording in x264

libobs: Fix incomplete struct in scaler call

Fix FMS authentication to support RTMP connection URLs that have a
query string parameter already.

Closes jp9000/obs-studio#1105

Closes jp9000/obs-studio#1106

UI: Add help portal link to help menu

Some audio devices do not have a fixed number of channels.  For example,
Soundflower.  This was previously fixed by defaulting the speaker layout
to stereo.  With surround sound support, the default has been changed to
the output speaker layout as set in Settings > Audio.

Closes jp9000/obs-studio#1110

The list of channel layouts available for decklink input is missing 2.1
& 4.1 layouts.  The commit adds them.  This aligns the decklink input
with the speaker layouts available at outputs.  Having different layouts
as input and output invokes FFmpeg resampler, which remixes the channels
in non trivial way except when downmixing to stereo.  This patch allows
to avoid such uncontrolled remix of channels with decklink input.

The core audio aac encoder has bitrates maps specific to speaker
layouts.  Previously, the bitrate map maxed at 320 kbs and was the map
for stereo.  The bitrate map is now tailored to the speaker layout.  In
practice this unlocks higher bitrates.  For instance up to 960 kbs for
7.1.  Additionally the commit fixes a bug with 2.1 with channels not
ordered correctly.

Bitrate map was previously maxed at 256 kbs which is OK for stereo.
This commit enables up to 1024 kbs which can be used for surround
channel layouts.

The click to select scenes follows the same rules
as the main UI. The double click respects the option
under Settings -> General -> Studio -> Transition
to scene when Double Clicked.

(also obs, deps/media-playback, libobs/audio-monitoring, decklink,
linux-alsa, linux-pulseaudio, mac-capture, obs-ffmpeg, win-dshow,
win-wasapi)

Default channel layout for 4 channels is 4.0 in FFmpeg.
Replacing quad with 4.0 will improve compatibility since FFmpeg has
better support of its default channel layouts.

(also modifies obs-ffmpeg, audio-monitoring, win-wasapi, decklink,
obs-outputs)

Removes speaker layouts which are not exposed in UI.  The speaker
layouts selectable by users in the UI are the most common ones.  It is
not necessary to keep other layouts.  (This basically removes
5POINT1_SURROUND, 7POINT1_SURROUND, SURROUND =3.0).