backward compatibility

[Kazu Yamamoto ( 山本和彦 )]

Hello,

> Yes, it's still on in GHC by default, but Cabal specifies Haskell98 if a
> language isn't given in the .cabal file.
> 
> network probably wants to give NondecreasingIndentation as an extension
> if impl(ghc >= 7.1).

I'm not asking how to fix packages. Actually the layout of the network
package on github has been fixed today.

I'm asking why GHC breaks backward compatibility
(e.g. FlexibleInstances and BangPatterns) and why maintainers of
packages should do boring fixes. What are benefits of such overhead?

--Kazu