(Sending email failed) - 5.0Beta problem

[Lester Caine]

On Sun, 5 Aug 2007 01:52:25 -0500, Lester Caine <lester at LSCES.CO.UK> wrote:
>I have found what is different between 4.x and 5.0. It is not using the
>dynamic sizes provided with the URL. I had 'SIZE 600 600' but this is replaced
>by the sizes required for the actual page being rendered. In 5.0 this ability
>seems to have been lost, so I can't dynamically size the map window.

Cracked it
There were two 'spellings' of the size element in the url. 
'mapsize' and 'map_size'
Only the first is supported in 5.0 while both are accepted in 4.x 

Where is the changelog that would indicate these sorts of changes in 5.0?