Initial test 1630 added with basic HTTPS-proxy use. HTTPS-proxy is like
HTTP proxy but with a full TLS connection to the proxy.

Closes #5399

Fix theoretical integer overflow in Curl_auth_create_plain_message.

The security impact of the overflow was discussed on hackerone. We
agreed this is more of a theoretical vulnerability, as the integer
overflow would only be triggerable on systems using 32-bits size_t with
over 4GB of available memory space for the process.

Closes #5391

- Quote the globbing example URLs that contain characters [] {} since
  otherwise they may be interpreted as shell metacharacters.

Bug: https://github.com/curl/curl/issues/5388
Reported-by: John Simpson

Closes https://github.com/curl/curl/pull/5394

Fine: "struct hello *world"

Not fine: "struct hello* world" (and variations)

Closes #5386

Added test 971 to verify that the list is in sync with the files in
cmdline-opts. The check also verifies that .d-files that uses Added:
specify the same version number as the options-in-versions file does.

Closes #5381

We boast support for 25 transfer protocols. Make sure the lists are
consistent

Closes #5384

... to avoid an OpenSSL bug that otherwise makes the CRL check to fail.

Reported-by: Michael Kaufmann
Fixes #5374
Closes #5376