[development] 4.7 maintenance: XHTML error in generated forms

[Gerhard Killesreiter]

Hi there!

The last patch on this issue was committed to Drupal HEAD in order to 
fix the problem. I'd like to backport this to 4.7, but I am concerned 
that changing the ID values might break things such as CSS and JS, two 
areas were my knowledge is meagre. Can anybody confirm or (even better) 
deny this suspicion? I this is an issue is there a 4.7 compatible way to 
fix this for 4.7 only?

Cheers,
    Gerhard