The device configuration widget is now the only place the user
ever has to specify ports.

Currently hidden.

This makes us more independent of the developer PC's firewall setting.

Reviewed-by: kh1

Task-number: QTCREATORBUG-1460

This is necessary in case there is no run configuration (e.g. for
library projects).

Reviewed-by: kh1

It does not conceptually belong there, and several people have
asked for an interface to use the functionality in their own
plugins.

Task-number: QTCREATORBUG-1204
Reviewed-by: kh1

Task-number: QTCREATORBUG-1074
Reviewed-by: kh1

This will replace the current ssh-via-QProcess approach, which
has severe drawbacks.

Most attributes have moved into the settings page.