Add ability to expose TCP connections

[mpociot]

This PR adds the ability to not only share HTTP connections, but also raw TCP connections.

The server will then assign a random port to the connection and forward all traffic from that port to the local destination port on the exposed computer.

Example:

expose share-port 2525

Todo:

• Add a new column to the users table to only allow TCP tunnels for specific users
• Make the port range configurable
• Attach TCP control connections to the auth token and show them in the API responses

[moisesh18]

Hi. With sharing TCP port feature activated, --subdomain option is allowed?.

UPDATE: I tried this new feature, but just realized that this PR is not in the master, since the last version (3.1.4) was released in Jul 28, and this post is from Sept 8. Thank u. I'l aware this feature!

[ldub]

hey @mpociot, sorry to revive a merged PR, but do you think you could do a release of expose sometime soon to include this code? tunneling tcp connections is super useful and i'm looking forward to this feature :)

[MeestorX]

Is TCP tunnelling part of this or not? It seems to have been merged, but as above, the share-port command doesn't work.