Remove the changes files already merged in Tor 0.2.8.6

changes/bug18397

-  o Minor bugfixes (Linux seccomp2 sandbox):
-    - Add a few missing syscalls to the seccomp2 sandbox: sysinfo,
-      getsockopt(SO_SNDBUF), and setsockopt(SO_SNDBUFFORCE). On
-      some systems, these are required for Tor to start with
-      "Sandbox 1" enabled.
-      Fixes bug 18397; bugfix on 0.2.5.1-alpha. Patch from
-      Daniel Pinto.

changes/bug19660

-  o Minor bugfixes (sandboxing):
-    - If we did not find a non-private IPaddress by iterating over
-      interfaces, we would try to get one via
-      get_interface_address6_via_udp_socket_hack().  This opens a
-      datagram socket with IPPROTO_UDP.  Previously all our datagram
-      sockets (via libevent) used IPPROTO_IP, so we did not have that
-      in the sandboxing whitelist.  Add (SOCK_DGRAM, IPPROTO_UDP)
-      sockets to the sandboxing whitelist.  Fixes bug 19660.

changes/bug19682

-  o Minor bugfixes (compilation):
-    - Fix compilation warning in the unit tests on systems where
-      char is signed. Fixes bug 19682; bugfix on 0.2.8.1-alpha.

changes/bug19782

-  o Minor bugfixes (fallback directories):
-    - Remove a fallback that was on the hardcoded list, then opted-out.
-      Fixes bug 19782; update to fallback list from 0.2.8.2-alpha.

changes/geoip-july2016

-  o Minor features:
-    - Update geoip and geoip6 to the July 6 2016 Maxmind GeoLite2
-      Country database.
-