changes in socketclient.js stops MMM-RemoteControl to work

[khassel]

The changes in socketclient.js introduced with this PR #1937 in v2.11.0 breaks MMM-RemoteControl, maybe other modules too.

See Jopyth/MMM-Remote-Control#185

After reverting the changes in socketclient.js the module works again.

[khassel]

Found 2 issues:

• we can't use window.location.pathname because modules can use own html sites referencing socketclient.js. E.g. in http://192.168.xxx.yyy:8080/remote.html window.location.pathname has the value /remote.html instead of expected /. This could may solved defining a subPath value in the config and using this value instead of window.location.pathname.

• in index.html the line
  <script type="text/javascript" src="/socket.io/socket.io.js"></script>
  was replaced in the above PR with
  <script type="text/javascript" src="socket.io/socket.io.js"></script>
  which is a good correction, but many module developers copied this line in their html site.
  This is a minor issue: If someone will use such a module with a subpath <> /, the above line must corrected in the module html.

[Legion2]

This can be resolved by defining a basename in the configuration with a default value of /. basename is the used instead of window.location.pathname.

[Legion2]

@khassel I created a PR to fix the broken socket.io path #1976

[MichMich]

Merged.