New command to publish assets

[tobyzerner]

From b26eb8e:

Extract publishing assets from the migrate command into a new command. Possible names:

• publish
• vendor:publish (this is what Laravel uses right?)
• asset(s):publish
• ...

Also will need to consolidate the publishing logic with the installer while we're at it.

[luceos]

I am in favor of asset:publish.

• Can we allow other extensions to hook into this command to be able to publish their extensions as well.
• I've also felt that the way vendor:publish works with the --provider or --tag flag was pretty overcomplicated, although it suits the frameworks needs.
• Maybe we can make this interactive once it grows too much by allowing the user to toggle what extension is allowed to publish?

[lubobill1990]

+1