Merge branch 'maint-0.2.9' into maint-0.3.1

diff --cc .travis.yml
index 19bbe6df01b18d7dac5d70ef427915794e08c640,6d314c1414be42e35f020fd57a0364f6f96d1b79..d6450d270bb8b7727704ec6162cdd669b84e5a28
--- 1/.travis.yml
--- 2/.travis.yml
+++ b/.travis.yml
@@@ -60,19 -60,28 +60,35 @@@ env
    global:
      ## The Travis CI environment allows us two cores, so let's use both.
      - MAKEFLAGS="-j 2"
 +  matrix:
 +    ## Leave at least one entry here or Travis seems to generate a
 +    ## matrix entry with empty matrix environment variables.  Leaving
 +    ## more than one entry causes unwanted matrix entries with
 +    ## unspecified compilers.
 +    - RUST_OPTIONS="--enable-rust --enable-cargo-online-mode"
 +    # - RUST_OPTIONS=""
  
  matrix:
-   ## If one build in the matrix fails (e.g. if building withour Rust and Clang
-   ## fails, but building with Rust and GCC is still going), then cancel the
-   ## entire job early and call the whole thing a failure.
-   fast_finish: true
+   ## Uncomment to allow the build to report success (with non-required
+   ## sub-builds continuing to run) if all required sub-builds have
+   ## succeeded.  This is somewhat buggy currently: it can cause
+   ## duplicate notifications and prematurely report success if a
+   ## single sub-build has succeeded.  See
+   ## https://github.com/travis-ci/travis-ci/issues/1696
+   # fast_finish: true
+ 
+   ## Uncomment the appropriate lines below to allow the build to
+   ## report success even if some less-critical sub-builds fail and it
+   ## seems likely to take a while for someone to fix it.  Currently
+   ## Travis CI doesn't distinguish "all builds succeeded" from "some
+   ## non-required sub-builds failed" except on the individual build's
+   ## page, which makes it somewhat annoying to detect from the
+   ## branches and build history pages.  See
+   ## https://github.com/travis-ci/travis-ci/issues/8716
+   allow_failures:
+     # - env: RUST_OPTIONS="--enable-rust" TOR_RUST_DEPENDENCIES=true
+     # - env: RUST_OPTIONS="--enable-rust --enable-cargo-online-mode
+     # - compiler: clang
  
    ## Create explicit matrix entries to work around a Travis CI
    ## environment issue.  Missing keys inherit from the first list