haskell-platform: install binaries and libraries into the user environment

Fixes https://github.com/NixOS/nixpkgs/issues/2968.
haskell-ariadne: update to version 0.1.2.3
haskell-language-c: update to version 0.4.7
haskell-rethinkdb: update to version 1.15.2.0
haskell-vty-ui: update to version 1.8
libfaketime: new package

Report faked system time to programs without having to change the
system-wide time.

http://www.code-wizards.com/projects/libfaketime/
nixos: increase allocated memory for gnome tests. Closes #4651
r-RcmdrPlugin.ROC: disable broken build