Implement PChan and switch utils/config to it

A PChan is a channel from Pipes.Concurrent wrapped in its own type.
Utilities/Config are refactored to use it.
Revert IO channel to TBQueue (from PChan)
Start refurbishing Node.hs
Pull asyncMany

Conflicts:
	src/Node.hs
	src/Utilities.hs
Add waiting function parameter to asyncMany
Refurbish ClientPool.hs
More polymorphic balanceEdges
Rename sealP -> seal
Rework send/receive/request
Refactoring, docs, remove most PChan utils
Refurbish Client.hs
Refurbish Server.hs
Refurbish message client
Refurbish node pool
README only
Refurbish Bootstrap.hs
Refurbish arg parser
Refurbish bootstrap server
Rework send/receive utilities

send/receive/request are simple functions once again, while their
continuous pipe-based counterparts are sender/receiver. A "requester"
may be useful but is not implemented right now.
Make startHandshakeH async exception safe