[Ide][Completion] Optimize right side description size and position

Author: sevoku

main/src/addins/CSharpBinding/MonoDevelop.CSharp.Completion/RoslynSymbolCompletionData.cs

@@ -92,7 +92,7 @@ public RoslynSymbolCompletionData (ICompletionDataKeyHandler keyHandler, RoslynC
 				if (returnType == null)
 					return null;
 				try {
-					return "<span font='Sans' size='x-small'>" + GLib.Markup.EscapeText (SafeMinimalDisplayString (returnType, factory.SemanticModel, ext.Editor.CaretOffset)) + "</span>";
+					return "<span font='Sans' size='small'>" + GLib.Markup.EscapeText (SafeMinimalDisplayString (returnType, factory.SemanticModel, ext.Editor.CaretOffset)) + "</span>";
 				} catch (Exception e) {
 					LoggingService.LogError ("Format error.", e);
 				}

main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.CodeCompletion/ListWidget.cs

@@ -598,8 +598,10 @@ protected override bool OnExposeEvent (Gdk.EventExpose args)
 
 						int w, h;
 						layout.GetPixelSize (out w, out h);
-						const int padding = 8;
-						w = Math.Min (w, Allocation.Width - textXPos - textW - padding);
+						const int leftpadding = 8;
+						const int rightpadding = 3;
+						w += rightpadding;
+						w = Math.Min (w, Allocation.Width - textXPos - textW - leftpadding);
 						wi += w;
 						typos = h < rowHeight ? ypos + (rowHeight - h) / 2 : ypos;
 						if (scalef <= 1.0)