Merge branch 'maint-0.2.9' into maint-0.3.5

diff --cc .travis.yml
index 4ded5e25a7b34fb1a688244757466160c42a3587,4ea9400b88937888e8a05b698a764601ac1cf4fd..7f0e785876befe84f3213ec317407cc80f5d4c5e
--- 1/.travis.yml
--- 2/.travis.yml
+++ b/.travis.yml
@@@ -145,19 -106,13 +145,20 @@@ addons
        ## Always installed, because manual brew installs are hard to get right
        - asciidoc
        - xmlto
 +      ## Utilities
 +      ## preventing or diagnosing hangs
 +      - timelimit
  
- ## (OSX only) Use the default OSX image
+ ## (OSX only) Use a recent macOS image
  ## See https://docs.travis-ci.com/user/reference/osx#os-x-version
- ## Default is Xcode 9.4 on macOS 10.13 as of August 2018
- #osx_image: xcode9.4
+ ## Default is Xcode 9.4 on macOS 10.13 as of October 2019
+ ## Recent is Xcode 11.2 on macOS 10.14 as of October 2019
+ osx_image: xcode11.2
  
 +before_install:
 +  ## Create empty rust directories for non-Rust builds, so caching succeeds
 +  - if [[ "$RUST_OPTIONS" == "" ]]; then mkdir -p $HOME/.cargo $TRAVIS_BUILD_DIR/src/rust/target; fi
 +
  install:
    ## If we're on OSX, configure ccache (ccache is automatically installed and configured on Linux)
    - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then export PATH="/usr/local/opt/ccache/libexec:$PATH"; fi