Add timeout options to the node connections.

[abizjak]

Purpose

Add timeout options for connections to the node to make it more robust in case of odd networking issues.

Checklist

• [x] My code follows the style of this project.
• [x] The code compiles without warnings.
• [x] I have performed a self-review of the changes.
• [x] I have documented my code, in particular the intent of the hard-to-understand areas.
• [x] (If necessary) I have updated the CHANGELOG.