[development] tagadelic 'backport' for 4.7

[Earl Miles]

Bèr Kessels wrote:
> I have been hit by this several times myself (most notable: I broke 40 sites 
> last month because suddenly the 4.7 image module was changed completely, it 
> took me a whole night of database-poking to get it streight again). So I 
> strongly and firmly beleive that a once-released module should only get 
> bugfixes and never, ever release completely overhauled code on that same 
> tag/branch. A new version belongs on a new 'place'. 

Thank dww, but we'll soonishly be getting the ability to actually do 
real releases and not this sort of moving tarball crud.