Vendor psutils and remove neko

plugins/system/ps/load/load_darwin.go

@@ -0,0 +1,37 @@
+// +build darwin
+
+package load
+
+import (
+	"strconv"
+
+	common "github.com/shirou/gopsutil/common"
+)
+
+func LoadAvg() (*LoadAvgStat, error) {
+	values, err := common.DoSysctrl("vm.loadavg")
+	if err != nil {
+		return nil, err
+	}
+
+	load1, err := strconv.ParseFloat(values[0], 64)
+	if err != nil {
+		return nil, err
+	}
+	load5, err := strconv.ParseFloat(values[1], 64)
+	if err != nil {
+		return nil, err
+	}
+	load15, err := strconv.ParseFloat(values[2], 64)
+	if err != nil {
+		return nil, err
+	}
+
+	ret := &LoadAvgStat{
+		Load1:  float64(load1),
+		Load5:  float64(load5),
+		Load15: float64(load15),
+	}
+
+	return ret, nil
+}