[development] t() placeholder changes in HEAD

[Steven Wittens]

A rather big patch was committed which affects t() in HEAD and thus 
pretty much every module out there. It's related to XSS and proper 
output conversion of text, so do pay attention ;).

The good news is, if you didn't care about check_plain() before, now 
some possible XSS holes should be automagically fixed.

For more info, see:
http://drupal.org/node/64279#t-placeholders

Steven Wittens