Fixes #150

Fixes https://github.com/turt2live/matrix-media-repo/issues/134

This can cause a panic of the process under the right conditions

There's a race condition where a stream might not be available if the media is remote and being downloaded. After a couple download attempts, it fixes itself. This will acquire a media stream if one isn't provided to ensure that a stream is always available to the consumer.

Fixes https://github.com/turt2live/matrix-media-repo/issues/142

Might be a fix for https://github.com/turt2live/matrix-media-repo/issues/92

There's some other functions which still need some work in order to fully complete the upload process

Another step forwards to having different storage backends. s3 uploads currently not implemented

 remove t2bot.io and add ipv6 addresses to blacklist

Fix typo in README

Fixes https://github.com/turt2live/matrix-media-repo/issues/136

Later support for MSC1711 will be done in https://github.com/turt2live/matrix-media-repo/issues/137

Fixes https://github.com/turt2live/matrix-media-repo/issues/126

Fixes https://github.com/turt2live/matrix-media-repo/issues/127

Fixes https://github.com/turt2live/matrix-media-repo/issues/129