remove shadow from message bubbles + fix padding

This shadow was not well displayed and a flat design is preferred.

Also, text in bubbles was too close to left border so padding is
increased.

Change-Id: Ib656d385bf54b82e38dcd14b4e96cfcde7c51a84
diff --git a/src/views/IMTableCellView.mm b/src/views/IMTableCellView.mm
index e8e874f..bf8b5cc 100644
--- a/src/views/IMTableCellView.mm
+++ b/src/views/IMTableCellView.mm
@@ -40,11 +40,15 @@
     [self.msgView setBackgroundColor:[NSColor clearColor]];
     [self.msgView setString:@""];
     [self.msgView setAutoresizingMask:NSViewWidthSizable];
-     [self.msgView setAutoresizingMask:NSViewHeightSizable];
+    [self.msgView setAutoresizingMask:NSViewHeightSizable];
     [self.msgBackground setAutoresizingMask:NSViewWidthSizable];
     [self.msgBackground setAutoresizingMask:NSViewHeightSizable];
     [self.msgView setEnabledTextCheckingTypes:NSTextCheckingTypeLink];
     [self.msgView setAutomaticLinkDetectionEnabled:YES];
+    [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-5-[msgView]-|"
+                                                                options:0
+                                                                metrics:nil
+                                                                  views:NSDictionaryOfVariableBindings(msgView)]];
    }
 
 - (void) updateWidthConstraint:(CGFloat) newWidth