IConsole.WriteLine should have a parameterless overload
ExecuteReplCommand.Execute should start a new line on exit
IConsole should have a `Clear' method
Entering `#clear' into the REPL should clear the console
Entering `#reset' in the REPL should reset the state of the REPL
Refactor Reset logic into a new Reset method on IScriptExecutor
Merge pull request #489 from jrusbatch/repl-exit

Print a new line when exiting the REPL
Merge pull request #490 from jrusbatch/repl-commands

Implement #reset and #clear in the REPL