Three patches for cabal

[Isaac Dupree]

Duncan Coutts wrote:
> In practise, since ghc uses MonoPatBinds by default it'd mean that
> people who want to get back to H98 would need to use:
> 
>   ghc-options: -XNoMonoPatBinds
> 
> Because the extensions field is additive, not subtractive. Using the
> name MonoPatBinds allows other compilers to implement it without it
> having to be the default.

hmm, that's annoying.  Is it feasible for the extensions field to allow 
both addition and subtraction that override compiler defaults?  (How 
does it work in LANGUAGE pragmas -- would NoMonoPatBinds still work in 
one of them?)

-Isaac