Add 401 and 403 error messages for put saver

[simonbaird]

Show the user a more useful message for the case where they're not
correctly authenticated and try to do a "put" save.

The context for this change is that I'm thinking about using the
put saver for TiddlyHost instead of the old upload saver, but it
should be generally useful.

Also includes a name change for the one existing error message. I
want to indicate these three messages are related, so I added the
"Put" prefix to make them appear next to each other in the language
files. (The Error/EditConflict string is used in just this one place
as far as I can tell.)

[simonbaird]

FYI @pmario @Jermolene . This will make the put saver more user friendly for TiddlyHost.

[simonbaird]

See also tiddlyhost/tiddlyhost-com#148 .

[Jermolene]

Hi @simonbaird that looks great. You don't need to worry about the translations; the translators tool picks up core strings that haven't been translated into a particular language.

[simonbaird]

The message could perhaps be more verbose, e.g.:

Permission denied. It appears you don't have permission to save this TiddlyWiki to {saveUrl}.

Authentication required. You need to authenticate in order to save this TiddlyWiki at {saveUrl}.

[simonbaird]

I also considered moving the messages to PutError/* instead of Error/* which would make sense if they were going to be specific to put saving.

[simonbaird]

Ack, will push a revision soon without the translations

[simonbaird]

Moving out of draft mode. There's a few changes since the original. Let me know if you don't like it.

[Jermolene]

Thanks @simonbaird, great stuff.

[simonbaird]

Awesome, thanks @Jermolene .