Initialize singleton components on system registration

[fernandojsg]

Many times we need to store data related to systems internally, a good practice to avoid storing data on the systems could be to use singleton components and add some syntactic sugar for that:

If we create a system in this way:

world.registerSystem(SystemA, {valueA: 1, valueB: 2});

it will create a singleton component named systemA (As if we had previously created a SystemA component with valueA and valueB attributes).
And we could access the component from within the system by referencing this.component:

execute() {
    this.component.valueA += 2;
}

[joshmarinacci]

Since you removed singletons should this be closed?

[fernandojsg]

Yes, I'll just close it by now and reopen if we feel we want to add it as syntactic sugar