Fetch RSS feeds via Tor
This patch replaces jsocks with our own minimal SOCKS 5 implementation, which is compatible with Android's OpenSSL hacks (see discussion on #599 (closed) for the horrifying details). This allows us to use OkHttp over Tor to fetch RSS feeds.
It turns out that SOCKS 5 without authentication is a really simple protocol: https://tools.ietf.org/html/rfc1928
Closes #599 (closed).