split DataStore into two plugins: Inputs and Outputs
extract CopyScript Plugin from WorkingDirectory and TemporaryDirectory
Context.run
Context.load_plugins
FIX: rename fixtures.Runner - it does not run anything
make CopyScript special: it takes an extra script directory parameter, which is not given to any other plugin
Postgres plugin: remove dependency on script_name, it should take its database name part from the script
remove script attributes name and dir
slightly simplify tests
Context.resolve_plugin_class(plugin_name)
Context.load_plugins works without explicit plugin class names (now: hard coded class names inside)
script syntax change: it is a YaML stream with one document per one plugin
script syntax change: script is a YaML stream with one document per one plugin, plugin order matters