[FEATURE REQUEST] Support unique admin path (instead of 'admin')

[TheDarkula]

Having the /admin endpoint listening on the same port is a security risk.

Separating the two services into something like ports 3000 and 4000 would be ideal, as this could easily be routed to a separate host, such admin.shop.com.

[tudors-services]

Wouldn't be easier to modify the route that it listens to and make something random or even a different naming ? Having on different port might create problems if firewalls are involved.

[treoden]

EverShop organizes both Admin and Front store on same node. Let's see if we can let use define the path for the admin to make it hard for guessing