Merge r1870553, r1870555, r1871091, r1871095, r1871141, r1871815, r1871816, r1871907...

Merge r1870553, r1870555, r1871091, r1871095, r1871141, r1871815, r1871816, r1871907, r1871908, r1872045, r1872063, r1872073, r1872106, r1872124, r1872309, r1872372, r1872373, r1872389, r1872392, r1872519, r1872544, r1872588, r1872590 from trunk:

Skip "PCRE 1" job for 2.4.x since there's no PCRE 2 support.

Enable ppc64le builds, caching now seems to work in Travis for non-x86.

travis: enable email notifications on success as test

adding myself for debugging (happy 113th birthday to the inventor of that term\!)

does this work??

travis: send notification to httpd-dev@ only on failure

Due to a combination of Daniel's work and probably some fix
on Travis end, we are now finally getting Travis emails in
httpd-dev@. Since having notifications for successful builds
might become a little spammy, let's just alert when a build
fails (like we do with buildbot IIUC).

travis: sync trunk's notification config with 2.4.x

test/travis_before_linux.sh: add a simple bash retry to svn export

Sometimes a build is killed by Travis due to svn export taking
a long time to complete (> 10m). This change should be a test to see
if a simple workaround reduces the noise to the dev@ mailing list.

test/travis_before_linux.sh: remove bash -e flag

To allow a proper fail/retry, -e needs to be removed.
Ideally this shouldn't happen, so I'd consider this
a test to see if the bash for workaround is a viable
option or not.

test/travis_before_linux.sh: make for loop more resilient

This is a follow up to my last commit to this file, to make
the for loop more resilient with the following:
- use --force in svn export, otherwise the second attempt will
  always fail due to the dest directory already present.
- exit 1 in case the 5 tries end up in a non zero exit code
  (to fail fast the build).

travis: temporary disable notifications to dev@

There seem to be some issues to iron out, disabling
email notifications to avoid spamming dev@.

test/travis_before_linux.sh: move retry logic to function

Move the retry logic to a bash function and restore the -e
failure policy in the script (to have cleaner log traces
in base of build failures).

Work around a build failure when a cached APR branch install
is used but APR-util needs to be rebuilt; currently this fails
because the APR build directory is not available.

e.g. https://travis-ci.org/apache/httpd/jobs/630885203

Disable caching for this combination for now.

travis: restore email notifications for dev@

The issue with ppcle64 seems to be fixed from [1],
and Joe fixed the APR 1.7.x issue as well. Builds are
back to normal.

[1]: https://travis-ci.community/t/ppc64le-an-error-occurred-while-generating-the-build-script/6598/6

test/travis_before_linux.sh: increase backoff time before executing svn export

Cache SVN checkout of test/framework across Travis builds.  Should
improve reliability (the checkout fails frequently) and performance,
plus reduces load on ASF infra.

Github: closes #85

Add Travis job which runs tests in random order.

Github: closes #86

travis: add verbose config to perl test suite for Ubuntu Worker All Modules

For some reason we get sporadic failures only in Ubuntu Worker All Modules' test:

t/apache/rwrite.t ................... 53/? # Failed test 113 in /home/travis/build/apache/httpd/test/perl-framework/blib/lib/Apache/TestCommon.pm at line 56 fail #113
t/apache/rwrite.t ................... Failed 1/114 subtests

Recent examples:
https://travis-ci.org/apache/httpd/jobs/632425202
https://travis-ci.org/apache/httpd/jobs/633250739

Add "-verbose" as test option to capture more data about the failure
when it happens.

travis: disable email notifications

There are still some spurious failures to iron out,
turn off email notification to avoid too many failure
emails to dev@.

Add arm64 support for Travis testing.
This support is experimental.

travis: remove verbose arg for Ubuntu Worker

Add Travis job running the litmus WebDAV test suite.

Enable verbose test output to debug failures on arm.

Submitted by: jorton, elukey, humbedoohy, mrumph
Github: closes #90

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1872757 13f79535-47bb-0310-9956-ffa450edef68