Document that we require a C++11 compiler
Update release notes
Include position info in function application

This allows error messages like:

  error: the anonymous function at `/etc/nixos/configuration.nix:1:1'
    called without required argument `foo', at
    `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/lib/modules.nix:77:59'
Remove unnecessary quotes around file names
Pass position information to primop calls

For example:

  error: `tail' called on an empty list, at
    /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/ex-2/default.nix:13:7
forceInt: Show position info
forceList: Show position info
forceAttrs: Show position info
forceString: Show position info
derivation: Don't require certain function arguments

Turns out that in Nixpkgs, derivation is actually called without a
‘name’ argument in some places :-(
Show position info in string concatenation / addition errors
Show position info in Boolean operations
Show position info in attribute selection errors