curl: --help [option] displays documentation for given cmdline option

Since the documentation text blob might be gzipped, it needs to search
for what to output in a streaming manner. It

curl: --help [option] displays documentation for given cmdline option

Since the documentation text blob might be gzipped, it needs to search
for what to output in a streaming manner. It then first searches for
"\nALL OPTIONS".

Then, it looks for the start to display at "\n -[option]" and stops
again at "\n -". Except for the last option in the man page, which
ends at "\nFILES" - the subtitle for the section following all options
in the manpage.

Test 1707 to 1710 verify

Closes #13997

show more ...

cmdline-opts: category cleanup

Option cleanups:

--get is not upload
--form* are post
- added several options into ldap, smtp, imap and pop3
- shortened the category

cmdline-opts: category cleanup

Option cleanups:

--get is not upload
--form* are post
- added several options into ldap, smtp, imap and pop3
- shortened the category descriptions in the list

category curl fixes:

--create-dirs removed from 'curl'
--ftp-create-dirs removed from 'curl'
--netrc moved to 'auth' from 'curl'
--netrc-file moved to 'auth' from 'curl'
--netrc-optional moved to 'auth' from 'curl'
--no-buffer moved to 'output' from 'curl'
--no-clobber removed from 'curl'
--output removed from 'curl'
--output-dir removed from 'curl'
--remove-on-error removed from 'curl'

Add a "global" category:

- Made all "global" options set this category

Add a "deprecated" category:

- Moved the deprecated options to it (maybe they should not be in any
category long term)

Add a 'timeout' category

- Put a number of appropriate options in it

Add an 'ldap' category

- Put the LDAP related option in there

Remove categories "ECH" and "ipfs"

- They should not be categories. Had only one single option each.

Remove category "misc"

- It should not be a category as it is impossible to know when to browse
it.

--use-ascii moved to ftp and output
--xattr moved to output
--service-name moved to auth

Managen fixes:

- errors if an option is given a category name that is not already setup
for in code

- verifies that options set `scope: global` also is put in category
`global´

Closes #14101

show more ...

code: language cleanup in comments

Based on the standards and guidelines we use for our documentation.

- expand contractions (they're => they are etc)
- host name = > hostname

code: language cleanup in comments

Based on the standards and guidelines we use for our documentation.

- expand contractions (they're => they are etc)
- host name = > hostname
- file name => filename
- user name = username
- man page => manpage
- run-time => runtime
- set-up => setup
- back-end => backend
- a HTTP => an HTTP
- Two spaces after a period => one space after period

Closes #14073

show more ...

TLS: add support for ECH (Encrypted Client Hello)

An EXPERIMENTAL feature used with CURLOPT_ECH and --ech.

Closes #11922

tests: remove leading spaces from some tags

The threee tags `<name>`, `</name>` and `<command>` were frequently used
with a leading space that this removes. The reason this habbit is so

tests: remove leading spaces from some tags

The threee tags `<name>`, `</name>` and `<command>` were frequently used
with a leading space that this removes. The reason this habbit is so
widespread in testcases is probably that they have been copy and pasted.

Hence, fixing them all now might curb this practice from now on.

Closes #12028

show more ...

tool_help: make "output" description less confusing

Currently the description of "output" is misleading when comparing it
"verbose".

Closes #6118

tests: Add tests for new --help

This commit is a part of "--help me if you can"

Closes #5680