Command::IsFinished() must be overriden by subclasses again (#353)

Documentation was added for InstantCommand and TimedCommand.

wpilibc/shared/src/Commands/Command.cpp

@@ -207,24 +207,6 @@ void Command::Execute() {}
  */
 void Command::End() {}
 
-/**
- * Returns whether this command is finished.
- * If it is, then the command will be removed and {@link Command#end() end()}
- * will be called.
- *
- * <p>It may be useful for a team to reference the {@link Command#isTimedOut()
- * isTimedOut()} method for time-sensitive commands.</p>
- *
- * <p>By default this will always return false, which means it will never end
- * automatically. It may still be cancelled manually or interrupted by another
- * command. For most real-world scenarios you will override this method with
- * additional logic.</p>
- *
- * @return whether this command is finished.
- * @see Command#isTimedOut() isTimedOut()
- */
-bool Command::IsFinished() { return false; }
-
 /**
  * Called when the command ends because somebody called
  * {@link Command#cancel() cancel()} or another command shared the same