uses property type ctor overload to accept an alias which prob should have been there all along since in most cases you need an alias to create one (same prob goes for property groups, etc... but oh well). Adds a couple tests for case insensitive comparisons in PropertyCollection

src/Umbraco.Core/Services/PackagingService.cs

@@ -648,9 +648,8 @@ namespace Umbraco.Core.Services
                     if (dataTypeDefinition == null) continue;
                 }
 
-                var propertyType = new PropertyType(dataTypeDefinition)
+                var propertyType = new PropertyType(dataTypeDefinition, property.Element("Alias").Value)
                                        {
-                                           Alias = property.Element("Alias").Value,
                                            Name = property.Element("Name").Value,
                                            Description = property.Element("Description").Value,
                                            Mandatory = property.Element("Mandatory").Value.ToLowerInvariant().Equals("true"),