Add Network (NIC) support (updated) (#52)

* [Core] Add Network (NIC) support - All credits to XiaofengdiZhu (https://github.com/XiaofengdiZhu/openhardwaremonitor/commits/EditeByXiaofengdizhu)

* [Core] NIC: Rename InternetSpeed to Throughput, drop non physical devices (like loopback), fix alltime stats for adapter

GUI/SensorNode.cs

@@ -29,6 +29,38 @@ namespace OpenHardwareMonitor.GUI {
         if (sensor.SensorType == SensorType.Temperature && 
           unitManager.TemperatureUnit == TemperatureUnit.Fahrenheit) {
           return string.Format("{0:F1} °F", value * 1.8 + 32);
+        } else if(sensor.SensorType == SensorType.Throughput){␍          string result = "-";
+          switch (sensor.Name){ 
+            case "Connection Speed": {
+              switch (value){ 
+                case 100000000:
+                    result = "100Mbps";
+                    break;
+                case 1000000000:
+                    result = "1Gbps";
+                    break;
+                default: {
+                  if (value < 1024)
+                      result = string.Format("{0:F0} bps", value);
+                  else if (value < 1048576)
+                      result = string.Format("{0:F1} Kbps",value/1024);
+                  else if (value < 1073741824)
+                      result = string.Format("{0:F1} Mbps",value/1048576);
+                  else
+                      result = string.Format("{0:F1} Gbps",value/ 1073741824);
+                } break;
+              }
+            }
+            break;
+            default:{
+              if (value<1048576)
+                  result = string.Format("{0:F1} KB/s",value/1024);
+              else
+                  result = string.Format("{0:F1} MB/s",value/1048576);
+            }
+            break;
+          }
+          return result;
         } else {
           return string.Format(format, value);
         }                
@@ -55,6 +87,7 @@ namespace OpenHardwareMonitor.GUI {
         case SensorType.SmallData: format = "{0:F1} MB"; break;
         case SensorType.Factor: format = "{0:F3}"; break;
         case SensorType.Frequency: format = "{0:F1} Hz"; break;
+        case SensorType.Throughput: format = "{0:F1} B/s"; break;
       }
 
       bool hidden = settings.GetValue(new Identifier(sensor.Identifier,