Add support for upgrade via SFTP (SSH File Transfer Protocol)

[Huvet]

To reproduce:

1. In dashboard: Click Tools -> Update
2. Fill in SFTP account information
3. Click proceed

Result:
"Error: There was an error connecting to the server, Please verify the settings are correct."

I have verified that the account information is correct by successfully connecting with both ​FileZilla and ​PyTTy.

What more information do you need to troubleshoot this further?

[DD32]

try using localhost or 127.0.0.1 for the hostname, see if that helps you.

[Huvet]

Same error using either localhost or 127.0.0.1. Anything else I should try?

[Huvet]

Ah, I see what the problem is, FTPS is not the same as SFTP, silly me. As the title says, I only have access to my host via SFTP, not FTPS (trying that in FileZilla makes the connection fail too).

So this bug is then transformed from a bug to a feature request.

[ryan]

2.7 supports SFTP if you have the ssh2 php extension installed.

[Huvet]

Thanks, I'll look into that. Would be useful with a note of that on the upgrade page.