[commit: base] type-nats's head updated: Merge remote-tracking branch 'origin/master' into type-nats (1dc904c)

[Iavor Diatchki]

Repository : ssh://darcs.haskell.org//srv/darcs/packages/base

Branch 'type-nats' now includes:

     531c09e... Add strict versions of modifyIORef and atomicModifyIORef
     d80a66f... Update gitignore
     1dc904c... Merge remote-tracking branch 'origin/master' into type-nats