Improve permalinks settings error messages

[sabernhardt]

On ticket:40763#comment:6, @johnbillion recommended the removal of Ctrl + A and "we" wording for error messages about an unwritable file or root directory.

Screenshots (forcing the errors in options-permalink.php, as described in ticket:53142#comment:7):

See also #40582

[sabernhardt]

53141.diff​ also adds error prefixes (as recommended in #50442).

web.config is not writable

1. Error: Your web.config file is not ​writable, so updating it automatically was not possible. Select and copy the URL rewrite rule below, and insert the entire code inside the /<configuration>/<system.webServer>/<rewrite>/<rules> element in the web.config file.
2. If you temporarily make your web.config file writable to generate rewrite rules automatically, do not forget to revert the permissions after rule has been saved.

root directory is not writable to edit web.config

1. Error: The root directory of your site is not ​writable, so creating a file automatically was not possible. Create a new file called web.config in the root directory of your site. Then select and copy the URL rewrite rule below, and insert the entire code into the web.config file.
2. If you temporarily make your site's root directory writable to generate the web.config file automatically, do not forget to revert the permissions after the file has been created.

.htaccess is not writable

1. Error: Your .htaccess file is not ​writable, so updating it automatically was not possible. Select and copy the mod_rewrite rules below, and insert the entire code inside the .htaccess file.

• Add "Error:" prefix to the first message in each situation.
• Split the first sentence into two, rephrasing it without "we" language.
• Capitalize "URL" in two of the messages.
• Remove "for us" from the two messages about making the file or directory temporarily writable, and add "the" before "rule" in the web.config message.

Trac ticket: https://core.trac.wordpress.org/ticket/53141

[sabernhardt]

Updated text after r53047 (which added the Mac shortcut)

web.config is not writable

1. Error: Your web.config file is not ​writable, so updating it automatically was not possible. This is the URL rewrite rule you should have in your web.config file. Click in the field and press Ctrl + A (or ⌘ + A on Mac) to select all. Then insert this rule inside of the /<configuration>/<system.webServer>/<rewrite>/<rules> element in web.config file.
2. If you temporarily make your web.config file writable to generate rewrite rules automatically, do not forget to revert the permissions after the rule has been saved.

root directory is not writable to edit web.config

1. Error: The root directory of your site is not ​writable, so creating a file automatically was not possible. Create a new file called web.config in the root directory of your site. Then select and copy the URL rewrite rule below, and insert the entire code into the web.config file. Error: The root directory of your site is not ​writable, so creating a file automatically was not possible. This is the URL rewrite rule you should have in your web.config file. Create a new file called web.config in the root directory of your site. Click in the field and press Ctrl + A (or ⌘ + A) to select all. Then insert this code into the web.config file.
2. If you temporarily make your site's root directory writable to generate the web.config file automatically, do not forget to revert the permissions after the file has been created.

.htaccess is not writable

1. Error: Your .htaccess file is not ​writable, so updating it automatically was not possible. These are the mod_rewrite rules you should have in your .htaccess file. Click in the field and press Ctrl + A (or ⌘ + A on Mac) to select all.

[sabernhardt]

Three of these five strings already need translating in 6.0, so any further changes would be good to complete within the same cycle.

[peterwilsoncc]

In 53127:

Permalinks: Improve settings page error messages.

Props sabernhardt.
Fixes #53141.

Merged in https://core.trac.wordpress.org/changeset/53127, thanks.