Issue #257 - bugsplat crash.

In the debug version of WebRTC, it makes an explicit check that the number
of channels for an input device is between 1 and 2.  The release version allows
more, and should downmix if 1 channel is asked for.

This fix bumps up the max channels allowed to 8.

WebRTC logs now pass out of the webrtc library into a logging sink,
which converts them into SecondLife.log compatable logging calls.

This includes fatal errors and asserts, which are now logged into
SecondLife.log, and should be available in the crash logger.

New webrtc library fixes an assert in webrtc when echo cancellation is enabled or
disabled.

Also, fix an issue where disabling media grays out noise cancellation.

Migrate cubemaptoequirectangularm, dictionaries, emoji_shortcodes, glext, glh_linear, innosetup, jpegencoderbasic, threejs, tut to github

https://github.com/secondlife/autobuild/issues/46

Also remove temporary `continue-on-error` setting.

This reverts commit ab82d114.

Pull SLVoice from s3 so that the OSS build configurations work.

This reverts commit ab82d114.

There is a case where the custom audio processor, which is used to
determine audio levels, was disabled on connection shutdown even
when another connection was established.

This issue has been patched in the webrtc library.

Missed the second change... Here it is.

This reverts commit d07cd115.