Merge branch 'sg/travis-build-during-script-phase' into maint

Build the executable in 'script' phase in Travis CI integration, to follow the established practice, rather than during 'before_script' phase. This allows the CI categorize the failures better ('failed' is project's fault, 'errored' is build environment's). * sg/travis-build-during-script-phase: travis-ci: build Git during the 'script' phase