* Use rvalue move to receive accepted sockets
* Split asio dependent APIs to their own class and file
* Update documentation
* Organize code into different files
* Make some members private
* Rename things for clarity
* Use nullptr (C++11) instead of NULL.
* Put each file into its own namespace declaration.
* Remove "using namespace" directives and add scope qualifiers.
* Control when beast's implementation of std::equal (C++14) is used.
* Tidy up some const declarations.
Conflicts:
src/ripple_app/shamap/SHAMapSync.cpp
src/ripple_app/tx/TransactionEngine.cpp
* Determine location of database files in Config
* Inject database directory or file path in PeerFinder and Validators
* PeerFinder and Validators will share the same sqlite file
* Revise documentation in README.md
* Inject abstract_clock in Manager
* Introduce the Slot object as a replacement for Peer
* New bullet-proof method for slot accounting
* Replace Peer with Slot for tracking connections
* Prevent duplicate outbound connection attempts
* Improved connection and bootstrap business logic
* Refactor PeerImp, PeersImp private interfaces
* Give PeersImp access to the PeerImp interface
* Handle errors retrieving endpoints from asio sockets
* Use weak_ptr to manage PeerImp lifetime
* Better handling of socket closure in PeerImp
* Improve the orderly shutdown logic of PeersImp
* Implement PeerFinder business logic.
* Support fixed peers (including DNS support).
* Add journal support to Peer and Peers.
* Refactor PeerDoor support.
* Tidy up Peers and eliminate connection functionality and timers.
* Refactor Peer interface and add journal support.
* Allow construction of incoming Peer using an existing socket.
* Remove TESTNET support.
* Allow connections from/to cluster peers without consuming slots
* Misc. cleanups.
