collapse history of multiple calls to/from same peer

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

@@ -1,3 +1,10 @@
 package com.tutpro.baresip
 
-class HistoryRow(val peerURI: String, val direction: Int, val time: String)
+class HistoryRow(val peerURI: String, val direction: Int, val time: String) {
+
+    val directions = ArrayList<Int>()
+
+    init {
+        directions.add(direction)
+    }
+}