[feature] support processing of (many) more media types (#3090)

* initial work replacing our media decoding / encoding pipeline with ffprobe + ffmpeg

* specify the video codec to use when generating static image from emoji

* update go-storage library (fixes incompatibility after updating go-iotools)

* maintain image aspect ratio when generating a thumbnail for it

* update readme to show go-ffmpreg

* fix a bunch of media tests, move filesize checking to callers of media manager for more flexibility

* remove extra debug from error message

* fix up incorrect function signatures

* update PutFile to just use regular file copy, as changes are file is on separate partition

* fix remaining tests, remove some unneeded tests now we're working with ffmpeg/ffprobe

* update more tests, add more code comments

* add utilities to generate processed emoji / media outputs

* fix remaining tests

* add test for opus media file, add license header to utility cmds

* limit the number of concurrently available ffmpeg / ffprobe instances

* reduce number of instances

* further reduce number of instances

* fix envparsing test with configuration variables

* update docs and configuration with new media-{local,remote}-max-size variables

1 files changed, 0 insertions, 81 deletions

diff --git a/vendor/github.com/go-errors/errors/README.md b/vendor/github.com/go-errors/errors/README.md
deleted file mode 100644
index 2ee13f117..000000000
--- a/vendor/github.com/go-errors/errors/README.md
+++ /dev/null
@@ -1,81 +0,0 @@
-go-errors/errors
-================
-
-[![Build Status](https://travis-ci.org/go-errors/errors.svg?branch=master)](https://travis-ci.org/go-errors/errors)
-
-Package errors adds stacktrace support to errors in go.
-
-This is particularly useful when you want to understand the state of execution
-when an error was returned unexpectedly.
-
-It provides the type \*Error which implements the standard golang error
-interface, so you can use this library interchangably with code that is
-expecting a normal error return.
-
-Usage
------
-
-Full documentation is available on
-[godoc](https://godoc.org/github.com/go-errors/errors), but here's a simple
-example:
-
-```go
-package crashy
-
-import "github.com/go-errors/errors"
-
-var Crashed = errors.Errorf("oh dear")
-
-func Crash() error {
-    return errors.New(Crashed)
-}
-```
-
-This can be called as follows:
-
-```go
-package main
-
-import (
-    "crashy"
-    "fmt"
-    "github.com/go-errors/errors"
-)
-
-func main() {
-    err := crashy.Crash()
-    if err != nil {
-        if errors.Is(err, crashy.Crashed) {
-            fmt.Println(err.(*errors.Error).ErrorStack())
-        } else {
-            panic(err)
-        }
-    }
-}
-```
-
-Meta-fu
--------
-
-This package was original written to allow reporting to
-[Bugsnag](https://bugsnag.com/) from
-[bugsnag-go](https://github.com/bugsnag/bugsnag-go), but after I found similar
-packages by Facebook and Dropbox, it was moved to one canonical location so
-everyone can benefit.
-
-This package is licensed under the MIT license, see LICENSE.MIT for details.
-
-
-## Changelog
-* v1.1.0 updated to use go1.13's standard-library errors.Is method instead of == in errors.Is
-* v1.2.0 added `errors.As` from the standard library.
-* v1.3.0 *BREAKING* updated error methods to return `error` instead of `*Error`.
->  Code that needs access to the underlying `*Error` can use the new errors.AsError(e)
-> ```
->   // before
->   errors.New(err).ErrorStack()
->   // after
->.  errors.AsError(errors.Wrap(err)).ErrorStack()
-> ```
-* v1.4.0 *BREAKING* v1.4.0 reverted all changes from v1.3.0 and is identical to v1.2.0
-* v1.4.1 no code change, but now without an unnecessary cover.out file.