* fix: don't allow replacing pubkey
* fix: several small improvements
* removing pubkey setter
* improove error handling
* remove the use of Option[T] if not needed
* don't use optional
* fix-ci: temporarily pin p2pd to a working tag
* fix example to comply with latest changes
* bumping p2pd again to a higher version
* Bugfix: Dialing an already connected peer may lead to crash
* Introduced a standard_setup module allowing to instantiate
the `Switch` object in an easier manner.
* Added `Switch.disconnect(peer)`
* Trailing space removed (sorry about polluting the diff)