This example has repeatedly been reported to contain bugs, and as users
copy and paste code from this into production, I now deem it better to
not provide the example at all.

Closes #5090
Closes #5322

Show how curl_multi_poll() makes it even easier to use the multi
interface.

Closes #4596

Similar to multi-uv.c but using libevent 2. This is a simpler libevent
integration example then hiperfifo.c.

Closes #4471

Closes #4221

Ref: https://github.com/curl/curl/issues/3653
Ref: https://github.com/curl/curl/pull/3790

NOTE: This commit was cherry-picked and is part of a series of commits
that added the authzid feature for upcoming 7.66.0. The series was
temporarily reverted in db8ec1f so that it would not ship in a 7.65.x
patch release.

Closes https://github.com/curl/curl/pull/4186

- Revert all commits related to the SASL authzid feature since the next
  release will be a patch release, 7.65.1.

Prior to this change CURLOPT_SASL_AUTHZID  / --sasl-authzid was destined
for the next release, assuming it would be a feature release 7.66.0.
However instead the next release will be a patch release, 7.65.1 and
will not contain any new features.

After the patch release after the reverted commits can be restored by
using cherry-pick:

git cherry-pick a14d72c a9499ff 8c1cc36 c2a8d52 0edf690

Details for all reverted commits:

Revert "os400: take care of CURLOPT_SASL_AUTHZID in curl_easy_setopt_ccsid()."

This reverts commit 0edf6907ae37e2020722e6f61229d8ec64095b0a.

Revert "tests: Fix the line endings for the SASL alt-auth tests"

This reverts commit c2a8d52a1356a722ff9f4aeb983cd4eaf80ef221.

Revert "examples: Added SASL PLAIN authorisation identity (authzid) examples"

This reverts commit 8c1cc369d0c7163c6dcc91fd38edfea1f509ae75.

Revert "curl: --sasl-authzid added to support CURLOPT_SASL_AUTHZID from the tool"

This reverts commit a9499ff136d89987af885e2d7dff0a066a3e5817.

Revert "sasl: Implement SASL authorisation identity via CURLOPT_SASL_AUTHZID"

This reverts commit a14d72ca2fec5d4eb5a043936e4f7ce08015c177.

Allows an application to pass in a pre-parsed URL via a URL handle.

Closes #3227

- also update two URLs outside of docs/examples
- fix spelling of filename persistant.c
- fix three long lines that started failing checksrc.pl

Closes https://github.com/curl/curl/pull/3036

Closes #3030