[arch-haskell] PKGBUILDs for new gtk2hs

[Don Stewart]

dons:
> Hey all,
> 
> gtk2hs was cabalized and released on Hackage. It just works.
> 

And haskell-webkit.

Also, cabal2arch can generate these packages now directly with C libs
included (it now understands pkgconfig-depends: lines)

-- Don