Moved all API function definitions to Api object

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

@@ -25,29 +25,29 @@ class Call(val callp: Long, val ua: UserAgent, val peerUri: String, val dir: Str
     }
 
     fun connect(uri: String): Boolean {
-        return call_connect(callp, uri) == 0
+        return Api.call_connect(callp, uri) == 0
     }
 
     fun hold(): Boolean {
-        return call_hold(callp, true) == 0
+        return Api.call_hold(callp, true) == 0
     }
 
     fun resume(): Boolean {
-        return call_hold(callp, false) == 0
+        return Api.call_hold(callp, false) == 0
     }
 
     fun transfer(uri: String): Boolean {
-        val err = call_hold(callp, true)
+        val err = Api.call_hold(callp, true)
         if (err != 0)
             return false
         referTo = uri
-        return call_transfer(callp, uri) == 0
+        return Api.call_transfer(callp, uri) == 0
     }
 
     fun executeTransfer(): Boolean {
         return if (this.onHoldCall != null) {
-            if (call_hold(callp, true) == 0)
-                call_replace_transfer(this.onHoldCall!!.callp, callp)
+            if (Api.call_hold(callp, true) == 0)
+                Api.call_replace_transfer(this.onHoldCall!!.callp, callp)
             else
                 false
         } else
@@ -55,47 +55,33 @@ class Call(val callp: Long, val ua: UserAgent, val peerUri: String, val dir: Str
     }
 
     fun sendDigit(digit: Char): Int {
-        return call_send_digit(callp, digit)
+        return Api.call_send_digit(callp, digit)
     }
 
     fun notifySipfrag(code: Int, reason: String) {
-        call_notify_sipfrag(callp, code, reason)
+        Api.call_notify_sipfrag(callp, code, reason)
     }
 
     fun duration(): Int {
-        return call_duration(callp)
+        return Api.call_duration(callp)
     }
 
     fun stats(stream: String): String {
-        return call_stats(callp, stream)
+        return Api.call_stats(callp, stream)
     }
 
     fun audioCodecs(): String {
-        return call_audio_codecs(callp)
+        return Api.call_audio_codecs(callp)
     }
 
     fun replaces(): Boolean {
-        return call_replaces(callp)
+        return Api.call_replaces(callp)
     }
 
     init {
         if (ua.account.mediaEnc != "") security = R.drawable.box_red
     }
 
-    private external fun call_connect(callp: Long, peer_uri: String): Int
-    private external fun call_hold(callp: Long, hold: Boolean): Int
-    private external fun call_ismuted(callp: Long): Boolean
-    private external fun call_transfer(callp: Long, peer_uri: String): Int
-    private external fun call_send_digit(callp: Long, digit: Char): Int
-    private external fun call_notify_sipfrag(callp: Long, code: Int, reason: String)
-    private external fun call_start_audio(callp: Long)
-    private external fun call_audio_codecs(callp: Long): String
-    private external fun call_duration(callp: Long): Int
-    private external fun call_stats(callp: Long, stream: String): String
-    private external fun call_has_video(callp: Long): Boolean
-    private external fun call_replaces(callp: Long): Boolean
-    private external fun call_replace_transfer(xfer_callp: Long, callp: Long): Boolean
-
     companion object {
 
         fun calls(): ArrayList<Call> {