v0.3.0: Better node control

This release introduces the following features:

• Control interface, under node.ctrl: All functionalities later described,
  as well as the tid property, live in the control interface.
  The control interface is a named template mixin with name ctrl,
  meaning that names are accessing through the parent scope unless they
  conflict with other names (e.g. if an API define a tid function).
• Add the ability to suspend a node for a specified duration;
  The node can either drop requests, or delay them.
• Ability to filter requests: A node can be told to ignore certain endpoints.
• Request timeout: It is now possible to define a timeout on a client.
  An Exception will be thrown if the client time out.
• The annoying Serializing composite type [...] ArgWrapper won't show up again.