Address PR feedback

Remove unnecessary << operator overloading for CapDesc and update Host::startCapabilities to schedule each capability (via Host::scheduleCapabilityWorkLoop) rather post the work to the network thread (since the ~1s we save on network start via the post isn't noticeable in practice)

libp2p/Common.cpp

@@ -130,11 +130,6 @@ string reasonOf(DisconnectReason _r)
     }
 }
 
-ostream& operator<<(ostream& _out, CapDesc const& _capDesc)
-{
-    return _out << _capDesc.first << ": " << _capDesc.second;
-}
-
 void NodeIPEndpoint::streamRLP(RLPStream& _s, RLPAppend _append) const
 {
     if (_append == StreamList)

libp2p/Common.h

@@ -114,8 +114,6 @@ using CapDesc = std::pair<std::string, unsigned>;
 using CapDescSet = std::set<CapDesc>;
 using CapDescs = std::vector<CapDesc>;
 
-std::ostream& operator<<(std::ostream& _out, CapDesc const& _capDesc);
-
 /*
  * Used by Host to pass negotiated information about a connection to a
  * new Peer Session; PeerSessionInfo is then maintained by Session and can

libp2p/Host.cpp

@@ -156,12 +156,7 @@ void Host::startCapabilities()
 {
     for (auto const& itCap : m_capabilities)
     {
-        auto timer = itCap.second.backgroundWorkTimer;
-        auto cap = itCap.second.capability;
-        m_ioService.post([this, timer, cap]() {
-            cap->doBackgroundWork();
-            scheduleCapabilityWorkLoop(move(cap), move(timer));
-        });
+        scheduleCapabilityWorkLoop(itCap.second.capability, itCap.second.backgroundWorkTimer);
     }
 }