network enhanecment / refactor (#361)

* chore(network): improve connectivity check

* refactor(network): rewrite network and timesync component

* feat(display): show cloud connection status

* chore: change logging verbosity

* chore(websecure): update log message

* fix(ota): validate root certificate when downloading update

* feat(ui): add network settings tab

* fix(display): cloud connecting animation

* fix: golintci issues

* feat: add network settings tab

* feat(timesync): query servers in parallel

* refactor(network): move to internal/network package

* feat(timesync): add metrics

* refactor(log): move log to internal/logging package

* refactor(mdms): move mdns to internal/mdns package

* feat(developer): add pprof endpoint

* feat(logging): add a simple logging streaming endpoint

* fix(mdns): do not start mdns until network is up

* feat(network): allow users to update network settings from ui

* fix(network): handle errors when net.IPAddr is nil

* fix(mdns): scopedLogger SIGSEGV

* fix(dhcp): watch directory instead of file to catch fsnotify.Create event

* refactor(nbd): move platform-specific code to different files

* refactor(native): move platform-specific code to different files

* chore: fix linter issues

* chore(dev_deploy): allow to override PION_LOG_TRACE

internal/timesync/rtc.go

@@ -0,0 +1,26 @@
+package timesync
+
+import (
+	"fmt"
+	"os"
+)
+
+var (
+	rtcDeviceSearchPaths = []string{
+		"/dev/rtc",
+		"/dev/rtc0",
+		"/dev/rtc1",
+		"/dev/misc/rtc",
+		"/dev/misc/rtc0",
+		"/dev/misc/rtc1",
+	}
+)
+
+func getRtcDevicePath() (string, error) {
+	for _, path := range rtcDeviceSearchPaths {
+		if _, err := os.Stat(path); err == nil {
+			return path, nil
+		}
+	}
+	return "", fmt.Errorf("rtc device not found")
+}