Admin message levels are too ambigious

[Kaspars Sprogis]

Currently admin uses messages.INFO level for both - info messages and success messages.
But even text states it should be messages.SUCCESS instead of messages.INFO:
"The %(name)s "%(obj)s" was added successfully"

Therefore it is impossible to use different styles for these levels.

One more example:
In changelist, if you don't choose any checkbox and use some action, you receive message:
"Items must be selected in order to perform actions on them..."
which looks exactly like success messages and gives us feeling everything went ok, but it wasn't and this is confusing.

I suggest to correct these message levels, so that they are more precise and we could style them separately.
Patch is on it's way.

[Kaspars Sprogis]

Patch is available on my github branch. Opened PR.
See diff: ​https://github.com/darklow/django/compare/ticket_20111

[Kaspars Sprogis]

Since success and info message style are identical in admin, only noticable changes for users in current admin version will be warning messages.

I think this is more appropriate and precise:

Than current version:

[Kaspars Sprogis]

Link to pull request: ​https://github.com/django/django/pull/938

[twoolie]

I've looked over the patch. It's simple and solid. No tests/docs needed.

Marking Ready For Checkin as per ​https://docs.djangoproject.com/en/dev/internals/contributing/triaging-tickets/#ready-for-checkin

[Kaspars Sprogis <darklow@…>]

In 3be368c73e8e6696e7cc74421aeb4d06d8e828c8:

Fix #20111 Added more precise message level for succcess and warning messages