refactoring of messaging controller with new model

MessagesVC is now implemented using the new LRC model for
conversations.
 - Both views to display the messages (in call and off call)
   initialize their MessagesVC with the current conversation when
   needed.
 - A conversation caching system is introduced to not get the whole
   conversation::Info structure from LRC at each display request (once
   per message).

Change-Id: Ib520c1f88be78de37968d3d7741010f2c73f20ea
Reviewed-by: Kateryna Kostiuk <kateryna.kostiuk@savoirfairelinux.com>
diff --git a/src/ConversationVC.h b/src/ConversationVC.h
index cc170fe..887d8fb 100644
--- a/src/ConversationVC.h
+++ b/src/ConversationVC.h
@@ -18,6 +18,8 @@
  */
 
 #import <Cocoa/Cocoa.h>
+#import <api/conversation.h>
+#import <api/conversationmodel.h>
 
 @interface ConversationVC : NSViewController
 
@@ -32,4 +34,6 @@
  */
 @property (retain) NSString* message;
 
+- (void) setConversationUid:(const std::string)convUid model:(lrc::api::ConversationModel*)model;
+
 @end