[FFmpeg-devel] Added support for http_proxy

[Joel Holdsworth]

Previously, avformat/http only supported http proxy servers via the http_proxy environment variable.

This patch series add support for an "http_proxy" option in avformat/http, which enables per-stream tunnelling through an HTTP proxy server. This has applications within Kodi, where per-stream proxying is an often needed feature.

Additionally, this patch set adds http_proxy support to avformat/hls, and fixes a minor memory leak.