used public dochost for javadoc links

    deploys / publishes to public dochost
    changed zmt-build dependency to 2
    updated links added to javadoc

   to prevent non-deterministic simulation outcomes

EntityManager.java: preserves insertion order for component stores
DependencyGraph.java: preserves insertion order for independent nodes
    updated test

Entity.java
    added hasAlive method checking if still contained by manager

    made all methods have empty default implementation
        for more convenient implementation
EntityManager.java
    notifies listeners about added / removed components
    updated test

EntityManager.java
    added ListenerHandler for EntityListener objects
            previously in EntityCreationHandler
    updated test
removed EntityCreationHandler.java and test
    scheduling should be simulation specific and not done here
moved EntityFactory to parent package
    updated documentation
renamed EntityCreationListener to EntityListener
    changed parameters uuid / manager
removed package de.zmt.ecs.factory

        regardless if one of them is a subclass of Entity

EntitySystems.java
    added log message when resolving new order

        takes time in single threaded environments
        clean reimplementation needed if a single simulation
            uses multiple threads

Entity.java, EntityManager.java
    improved documentation
EntityCreationHandler.java
    added load method

build.gradle
    changed zmt-core dependency to 0.12.+

        in scheduler
    added test

    removed random parameter from create method
EntityCreateionHandler.java
    updated addEntity method
    removed field random and getter

    encapsulated fields with protected getters
    equals and hashCode will not skip uuid if null
         to make improperly deserialized objects throw NPEs

    only listeners that implement serializable are serialized

    by making EntitySystems serializable

EntitySystem.java
    added documentation regarding serialization
EntitySystems.java
    contains only one system per class
    added equals / hashCode method
    added MySerializationProxy class handling serialization
    updated test

    updated AbstractSystem, Entity, EntityManager.java
        and tests
EntityManager.java
    returning empty list and sets from Collections instead of new objects

    replaced project with zmt-core artifact reference
added .gitignore

    for components that are nested classes

    updated EntityCreationHandler