php54: add pcntl option
Fix backward compatibility with Nix < 1.6

"with" used to be less lazy, so don't rely on that.  Also don't use
the "<" operator.
Agda: update to 2.3.2.2.

This update also fixes the build errors on hydra that were caused by
an incompatible version of haskell-src-ext.

Close #1153.
Updating SlimerJS to Git version for compatibility with fresh xulrunner
libedit: add FreeBSD support
Improve description of the users.extraUsers.*.description option

Fixes NixOS/nixos#278.
Generate manual for i686-linux as well as x86_64-linux
haskell-OpenGL: update 2.9.x branch to version 2.9.1.0
haskell-gloss: update to version 1.8.1.1
haskell-xmobar: update to version 0.19
haskell-HDBC-postgresql: update to version 2.3.2.2
haskell-blaze-builder: update to version 0.3.2.0
haskell-constraints: update to version 0.3.4.2
haskell-fclabels: update to version 2.0.0.2
haskell-feed: update to version 0.3.9.2
haskell-hexpat: update to version 0.20.4
haskell-hslua: update to version 0.3.8
haskell-intervals: update to version 0.3
haskell-pipes-parse: update to version 2.0.1
haskell-postgresql-simple: update to version 0.3.9.1