[TYPO3-core] RFC #11822: Add warning for IE6 user

[Steffen Gebert]

Hi,

This is a SVN patch request.

Type: feature

Branches: trunk

BT reference:
http://bugs.typo3.org/view.php?id=11822

Problem:
IE6 might not be supported in future versions of TYPO3.
So it's already time to inform users, that their browser is outdated and  
they should update.

Solution:
Add a warning to login screen.

Note:
If #11370 (restyling of the login screen) would be in, this warning could  
look even nicer ;-)

Steffen