* #36914: New navigation working

This commit impacts the whole structure app, because we now have
nested Fragments. To keep retro-compatibility, we switched from normal
Fragment to Fragment from the support library.
diff --git a/src/org/sflphone/model/SipCall.java b/src/org/sflphone/model/SipCall.java
index d9db35a..479d833 100644
--- a/src/org/sflphone/model/SipCall.java
+++ b/src/org/sflphone/model/SipCall.java
@@ -49,7 +49,7 @@
     private CallContact contact = null;
     private boolean isRecording = false;
     private long timestamp_start = 0;
-
+    
 
     private int mCallType = state.CALL_TYPE_UNDETERMINED;
     private int mCallState = state.CALL_STATE_NONE;
@@ -299,8 +299,6 @@
             return this;
         }
 
-        private static final String TAG = SipCallBuilder.class.getSimpleName();
-
         public SipCallBuilder startCallCreation(String id) {
             bCallID = id;
             bCallType = SipCall.state.CALL_TYPE_INCOMING;