added account_[set_]sipnat API functions

added ua_update_account API function
go directly to settings of new account
fixed some main activity layout bugs
keep main activity interactive when screen is locked
removed aor from UserAgent class
added register method to UserAgent class
added foregrounded and isDeviceLocked util functions
updated libbaresip distribution

app/src/main/kotlin/com/tutpro/baresip/Utils.kt

@@ -1,11 +1,17 @@
 package com.tutpro.baresip
 
+import android.app.ActivityManager
 import android.content.Context
 import android.support.v7.app.AlertDialog
 import android.util.Log
 import android.net.ConnectivityManager
 
 import java.io.*
+import android.os.Build
+import android.os.PowerManager
+import android.app.KeyguardManager
+
+
 
 object Utils {
 
@@ -127,6 +133,30 @@ object Utils {
         }
     }
 
+    fun foregrounded(): Boolean {
+        val appProcessInfo = ActivityManager.RunningAppProcessInfo()
+        ActivityManager.getMyMemoryState(appProcessInfo);
+        return ((appProcessInfo.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND) or
+                (appProcessInfo.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_VISIBLE))
+    }
+
+    fun isDeviceLocked(context: Context): Boolean {
+        val isLocked: Boolean
+
+        val keyguardManager = context.getSystemService(Context.KEYGUARD_SERVICE) as KeyguardManager
+        val inKeyguardRestrictedInputMode = keyguardManager.inKeyguardRestrictedInputMode()
+
+        if (inKeyguardRestrictedInputMode) {
+            isLocked = true
+        } else {
+            val powerManager = context.getSystemService(Context.POWER_SERVICE) as PowerManager
+            isLocked = !powerManager.isInteractive
+        }
+
+        Log.d("Baresip", "Now device is ${if (isLocked) "locked" else "unlocked"}")
+        return isLocked
+    }
+
     external fun cmd_exec(cmd: String): Int
     external fun uri_decode(uri: String): Boolean
     external fun audio_codecs(): String