Remove changes files that are already merged in 0.4.2.

changes/bug30344

-  o Minor bugfixes (connection):
-    - Avoid reading data from closed connections, which can cause needless
-      loops in libevent and infinite loops in Shadow. Fixes bug 30344; bugfix
-      on 0.1.1.1-alpha.

changes/bug31652

-  o Minor bugfixes (onion services):
-    - When we clean up intro circuits for a v3 onion service, don't remove
-      circuits that have an established or pending circuit even if ran out of
-      retries. This way, we don't cleanup the circuit of the last retry. Fixes
-      bug 31652; bugfix on 0.3.2.1-alpha.

changes/bug31734

-  o Minor bugfixes (error handling):
-    - Always lock the backtrace buffer before it is used.
-      Fixes bug 31734; bugfix on 0.2.5.3-alpha.

changes/bug31810

-  o Minor bugfixes (process management):
-    - Remove assertion in the Unix process backend. This assertion would trigger
-      when a new process is spawned where the executable is not found leading to
-      a stack trace from the child process. Fixes bug 31810; bugfix on 0.4.0.1-alpha.

changes/bug31837

-  o Minor bugfixes (testing):
-    - When testing port rebinding, don't busy-wait for tor to log. Instead,
-      actually sleep for a short time before polling again. Also improve the
-      formatting of control commands and log messages.
-      Fixes bug 31837; bugfix on 0.3.5.1-alpha.

changes/bug31922

-  o Minor bugfixes (configuration):
-    - When pkg-config is not installed, or a library that depends on
-      pkg-config is not found, tell the user what to do to fix the
-      problem. Fixes bug 31922; bugfix on 0.3.1.1-alpha.

changes/bug31939

-  o Minor bugfixes (tls, logging):
-    - Log TLS read buffer length bugs once, rather than filling the logs
-      with similar warnings. Fixes bug 31939; bugfix on 0.3.0.4-rc.

changes/bug31995

-  o Minor bugfixes (testing):
-    - Avoid intermittent test failures due to a test that had relied on
-      inconsistent timing sources. Fixes bug 31995; bugfix on 0.3.1.3-alpha.

changes/bug32124

-  o Minor bugfixes (build system):
-    - Stop failing when jemalloc is requested, but tcmalloc is not found.
-      Fixes bug 32124; bugfix on 0.3.5.1-alpha.
-    - Interpret --disable-module-dirauth=no correctly.
-      Fixes bug 32124; bugfix on 0.3.4.1-alpha.
-    - Interpret --with-tcmalloc=no correctly.
-      Fixes bug 32124; bugfix on 0.2.0.20-rc.

changes/ticket29669

-  o Minor feature (hidden service, control port):
-    - The ADD_ONION key blob keyword "BEST" now defaults from RSA1024 (v2) to
-      ED25519-V3 (v3). Closes ticket 29669.

changes/ticket30860

-  o Testing:
-    - Run the chutney IPv6 networks as part of Travis CI.
-      Closes ticket 30860.

changes/ticket31091

-  o Minor bugfixes (pluggable transports):
-    - Remove overly strict assertions that triggers when a pluggable transport
-      is spawned in an unsuccessful manner. Fixes bug 31091; bugfix on 0.4.0.1-alpha.

changes/ticket31189

-  o Documentation:
-    - Correct the description of "GuardLifetime". Fixes bug 31189; bugfix on
-      0.3.0.1-alpha.

changes/ticket31548

-  o Major bugfixes (hidden service v3):
-    - Make onion service always use the exact amount of configured intro points
-      (or less due to node exlusion). Before, a service could sometimes pick
-      more intro points than configured with the
-      HiddenServiceNumIntroductionPoints option. Fixes bug 31548; bugfix on
-      0.3.2.1-alpha.
-

changes/ticket31682

-  o Minor bugfixes (hidden service v3, coverity):
-    - Fix an implicit conversion from ssize_t to size_t discovered by Coverity.
-      Fixes bug 31682; bugfix on 0.4.2.1-alpha.

changes/ticket31841

-  o Minor features (testing):
-    - When running tests that attempt to look up hostname, replace the libc
-      name lookup functions with ones that do not actually touch the network.
-      This way, the tests complete more quickly in the presence of a slow or
-      missing DNS resolver. Closes ticket 31841.

changes/ticket31859

-  o Testing:
-    - Simplify the Travis CI build matrix, and optimise for build time.
-      Closes ticket 31859.

changes/ticket32058

-  o Minor bugfixes (mainloop, periodic events):
-    - Periodic events enabled flag was not unset properly when shutting down tor
-      cleanly. This had the side effect to not re-enable periodic events when
-      tor_api.h is used to relaunch tor after a shutdown. Fixes bug 32058;
-      bugfix on 0.3.3.1-alpha.

changes/ticket32063

-  o Minor bugfixes (hs-v3, memory leak):
-    - Fix memory leak in unlikely error code path when encoding HS DoS establish
-      intro extension cell. Fixes bug 32063; bugfix on 0.4.2.1-alpha.

changes/ticket32086

-  o Testing:
-    - Use Windows Server 2019 instead of Windows Server 2016 in our
-      Appveyor builds. Closes ticket 32086.