weaved: Add logging for network/soft AP setup/teardown

Added a few useful log messages to mark the moment when soft AP
is started/stopped and when new WiFi network is setup in order to
help with debugging networking events.

Change-Id: Iec9b335f8accc07714d5f37b7eb4a4e5b0368023
diff --git a/buffet/shill_client.cc b/buffet/shill_client.cc
index b9e0080..8ee5bca 100644
--- a/buffet/shill_client.cc
+++ b/buffet/shill_client.cc
@@ -138,6 +138,7 @@
 void ShillClient::Connect(const string& ssid,
                           const string& passphrase,
                           const weave::DoneCallback& callback) {
+  LOG(INFO) << "Connecting to WiFi network: " << ssid;
   if (connecting_service_) {
     weave::ErrorPtr error;
     weave::Error::AddTo(&error, FROM_HERE, kErrorDomain, "busy",
@@ -201,10 +202,12 @@
 }
 
 void ShillClient::StartAccessPoint(const std::string& ssid) {
+  LOG(INFO) << "Starting Soft AP: " << ssid;
   ap_manager_client_->Start(ssid);
 }
 
 void ShillClient::StopAccessPoint() {
+  LOG(INFO) << "Stopping Soft AP";
   ap_manager_client_->Stop();
 }