Add CommandDispatcher (fixes #21)

Assets/Scripts/Logic.meta

Assets/Scripts/Logic/Command.meta

Assets/Scripts/Logic/Command/BaseCommand.cs

Assets/Scripts/Logic/Command/BaseCommand.cs.meta

Assets/Scripts/Logic/Command/BiCommandResult.cs

Assets/Scripts/Logic/Command/BiCommandResult.cs.meta

Assets/Scripts/Logic/Command/CommandDispatcher.cs

Assets/Scripts/Logic/Command/CommandDispatcher.cs.meta

Assets/Scripts/Logic/Command/ICommandResult.cs

Assets/Scripts/Logic/Command/ICommandResult.cs.meta

Assets/Scripts/Logic/Event.meta

Assets/Scripts/Logic/Logic.asmdef

Assets/Scripts/Logic/Logic.asmdef.meta

Assets/Scripts/LogicTests.meta

Assets/Scripts/LogicTests/CommandDispatcherTest.cs

Assets/Scripts/LogicTests/CommandDispatcherTest.cs.meta

Assets/Scripts/LogicTests/LogicTests.asmdef

Assets/Scripts/LogicTests/LogicTests.asmdef.meta

ProjectSettings/ProjectSettings.asset

ProjectSettings/TimelineSettings.asset