use constructor.name property by default for custom name, if defined

[cozyazure]

For ES6, constructor's name will be the same as the class name of an object, and it will be stored under the __proto__.constructor.name. If this is defined, use this custom name instead.

[katanacrimson]

Any way this could make its way into a new release? 0.6.0 is out there, with these commits dangling off of master.

[mohsen1]

I'll cut a release today

[katanacrimson]

Thanks much!

[mohsen1]

Released in v0.7.0