transmission: Update to 2.93 + fixes [v2]

transmission: Update to 2.93 + fixes [v2]
DNS rebinding protection introduced a new option. Use it to disable it as OpenWrt does not need it.

Adjusted Makefile to use the release instead of a git version. Also cleaned up and added LICENSE entries.

Eliminated useless patches. The syslog one actually doesn't log much. No need to mask the os release anymore either.

Added group entry to init script. Otherwise files end up being owned by user:root which is bogus.

v2: Previous maintainer relied on git version of Transmission for mbedtls support. Backport it to the stable instead.

Signed-off-by: Rosen Penev <rosenp@gmail.com>