Changelog for repl-toolkit-0.5.0.0

0.5 Replaced system-filepath with filepath, as system-filepath has become deprecated. This is a minor, but breaking, change. 0.4 Completely overhauled the command system. It is now possible to chain commands together and make subcommands. 0.3.1 Added functionality for reading configuration files. 0.3 Ditched MonadError in favour of MonadThrow. This should make the functions much easier to use.