Shorten class exports for singleton files

I guess this one is a bit controversial. file size VS readability.

for a normal class we are doing:

Neo.setupClass(ServiceBase);

export default ServiceBase;

for a singleton it changes to:

let instance = Neo.setupClass(App);

export default instance;

=> setupClass() will return an instance if (and only if) the singleton config is set to true.

while the code will shorten when getting minified:

let i = Neo.setupClass(App);

export default i;

i would still prefer:

export default Neo.setupClass(App);

rationale: you don't define variables for things you only use once.