Release 1.6.1

Change-Id: Iaa6cc5bb06e715aafb3ecab86ae7cde6ef30413d

This commit was bulk generated and pushed by the OpenDev sysadmins
as a part of the Git hosting and code review systems migration
detailed in these mailing list posts:

http://lists.openstack.org/pipermail/openstack-discuss/2019-March/003603.html
http://lists.openstack.org/pipermail/openstack-discuss/2019-April/004920.html

Attempts have been made to correct repository namespaces and
hostnames based on simple pattern matching, but it's possible some
were updated incorrectly or missed entirely. Please reach out to us
via the contact information listed at https://opendev.org/ with any
questions you may have.

...then switch CentOS job to be a voting gate job instead of
experimental.

Change-Id: I510e4da82deb779ece9ea5436b63c038a6c25b58

Apparently the author of our old crc32 assumed that shifting an int
to the right sign-extends, which is not always the case. Result is,
building and running make test on s390x fails. The fix is to force
a sign-extension using the "xor 0x80; sub 0x80" trick.

N.B. This does not cause a compatibility problem, because by a
miracle the "broken" crc32_alt was actually computing a stock
crc32, same that zlib has. Therefore, if someone, somewhere,
ran a Swift cluster on s390x with erasure coding policy,
the data in it is already stored with zlib checksums, as we
do it now anyway. This fix only permits the tests pass, which
used the bad data sample from x86.

Change-Id: Ibd5e4e6c02be00540a9648cc7e0f8efda275bf3f
Related-Change: Ib5ea2a830c7c23d66bf2ca404a3eb84ad00c5bc5
Related-Bug: 1666320

This popped up because Fedora mandates warning-free builds,
and get_chksum triggers a warning because it returns an
unaligned pointer (it is so analigned, static analysis in
the compiler can detect it).

The easiest fix is to remove it altogether. We think it should
be safe, because:

 - The function is not listed in any headers
 - Its counterpart is called "set_checksum", not "set_chksum"
 - PyECLib does not use it

We also hush some doxygen warnings about wrong comments.

Change-Id: Ie5bc736f912706e0ffd507765abd24e7f4761233

Install libraries to be tested w/ liberasurecode

Change-Id: Ic1cd7b61c780cf794640e4ce0d57e6126ad5756b

If LD_LIBRARY_PATH is set to any value, build will fail, example:
Making check in doc
...
/bin/bash: line 1: /usr/lib/libeatmydata: No such file or directory
...

See: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=906480

Same is true for DYLD_LIBRARY_PATH and DYLD_FALLBACK_LIBRARY_PATH.

This bug was introduced with commit 19442df2
where Kota removed evals, but forgot to remove prepending of same env
variables.

Change-Id: Ib7a1d6b839d4a207ee0471b55233e1ce5d958705

  - Build depend on libisal on amd64 archs to run unit tests during build
  - Build depend on libjerasure to run unit tests during build