Add support for checking multiple source types in Drag n Drop callback
to support overlays for linuxbrowser users. Once the "browsersource" is
available on the platform it will have priority.

Cube LUT file support

Support for URL/web link drag and drop 

Co-authored-by: NMatt Gajownik <matt@wizardcm.com>

librtmp: Allow partial success for mbedtls

UI: Fix audio restart message not hiding

UI: Display aspect ratios in video settings

Tested Cube LUT examples from Photoshop, Adobe spec, and some homebrew.

I don't know how to use the domain fields, so they are being ignored.

mbedtls_x509_crt_parse_path returns a positive number if it partially
succeeds and a negative number on complete failure. This changes the
positive result to no longer error and prevent TLS connections (OBS
verifies all endpoints so having no CA chain prevents TLS).

docs/sphinx: Fix obs_property_list_item_disable entry

obs-outputs: Fix mbedtls use of deprecated functions

mbedtls_md5_starts(), mbedtls_md5_update() and mbedtls_md5_finish()
have been marked deprecated since mbedtls version 2.7 and may go
away in the future.

These function have been superseded by versions with a return
value. They are suffixed with "_ret". We do not actually check
return values.

Also the header "mbedtls/net.h" has been superseded by
"mbedtls/net_sockets.h".

rtmp-services: Update/remove services

- Mixer OSL removed (NXDOMAIN)
- Restream.io Prague added (FTL & RTMP)
- GameTips.tv removed (NXDOMAIN on all servers)

This logs the Windows release version (e.g. 1809, 1903, etc)

This uses three methods of obtaining the actual windows version,
RtlGetVersion which is the ntdll version of GetVersionEx that bypasses
the manifest check garbage, looking up the file version of a file that
is most likely to be updated per windows version (ntoskrnl), and the
registry.  Of the three values, it chooses the highest windows version
obtained by the three.

Closes obsproject/obs-studio#2294

Leak fixes

Not sure if this is a valid pattern in the Qt world though.

Instruments claims there are still more around here, but they look
internal with my limited Mac knowledge.

CMake: Fix build on ppc64

obs-scripting: Add Python functions for frontend events

ppc64le was fixed before, but ppc64 (big-endian) was still failing.

libobs-opengl: Fix volume texture leak

obs-ffmpeg: Fix VC++ warnings

Supply Windows manifest file (incl. compatibility info)

Remove volume render targets

Unlikely to be necessary. Disable for simplicity.

Unlikely to be necessary. Disable for simplicity.

UI: Properly inform user if recording path is invalid