Version without memory leaks.

(cherry picked from commit 0e860da001e960e1b7cd4ca3ab9940a8dacd98de)

New linuxPackages_custom helper function

vim-plugins: add sensible

Disable tests for haskellngPackages.rematch since it is missing Specs mo...

Fix several haskellPackages build failures 

haskell-vector-fftw: new expression

Add a big bundle of packages from apple source releases. Many of them only provide headers or stubs, but are what's needed for the upcoming pure-darwin stdenv, and don't do any harm for now.

gccApple is dead. Leaving the top-level attribute for a little longer, but no need to keep its unused code.