Composer update - UI enhancements

- composer max height
- unread messages on scroll to bottom button
- changed input toolbar background
- new missed discussions notifications
- Edit a message mode
- Reply to a message mode
- support for landscape mode

Riot/Modules/Room/Views/InputToolbar/RoomInputToolbarView.h

@@ -59,6 +59,13 @@ typedef enum : NSUInteger
  */
 - (void)roomInputToolbarViewDidTapMediaLibrary:(MXKRoomInputToolbarView*)toolbarView;
 
+/**
+ Tells the delegate that the user wants to cancel the current edition / reply.
+ 
+ @param toolbarView the room input toolbar view
+ */
+- (void)roomInputToolbarViewDidTapCancel:(MXKRoomInputToolbarView*)toolbarView;
+
 @end
 
 /**
@@ -84,11 +91,21 @@ typedef enum : NSUInteger
 
 @property (weak, nonatomic) IBOutlet UIImageView *inputTextBackgroundView;
 
+@property (weak, nonatomic) IBOutlet NSLayoutConstraint *inputContextViewHeightConstraint;
+@property (weak, nonatomic) IBOutlet UIImageView *inputContextImageView;
+@property (weak, nonatomic) IBOutlet UILabel *inputContextLabel;
+@property (weak, nonatomic) IBOutlet UIButton *inputContextButton;
+
 /**
  Tell whether the filled data will be sent encrypted. NO by default.
  */
 @property (nonatomic) BOOL isEncryptionEnabled;
 
+/**
+ Sender of the event being edited / replied.
+ */
+@property (nonatomic, strong) NSString *eventSenderDisplayName;
+
 /**
  Destination of the message in the composer.
  */