Split Indexing in two disctint modules

- Added new Lucene module with Lucene.NET reference
- Banner message is displayed if no index service is enabled when Orchard.Indexing is active
- Added new MetadataExtensions for settings
- Blogs, Page and Sandbox aredefined as indexed during setup

--HG--
branch : dev

src/Orchard.Tests.Modules/Indexing/LuceneIndexProviderTests.cs

@@ -2,6 +2,7 @@
 using System.IO;
 using System.Linq;
 using Autofac;
+using Lucene.Services;
 using NUnit.Framework;
 using Orchard.Environment.Configuration;
 using Orchard.FileSystems.AppData;

src/Orchard.Tests.Modules/Indexing/LuceneSearchBuilderTests.cs

@@ -2,6 +2,7 @@
 using System.IO;
 using System.Linq;
 using Autofac;
+using Lucene.Services;
 using NUnit.Framework;
 using Orchard.Environment.Configuration;
 using Orchard.FileSystems.AppData;

src/Orchard.Tests.Modules/Orchard.Tests.Modules.csproj

@@ -130,6 +130,10 @@
       <Project>{9916839C-39FC-4CEB-A5AF-89CA7E87119F}</Project>
       <Name>Orchard.Core</Name>
     </ProjectReference>
+    <ProjectReference Include="..\Orchard.Web\Modules\Lucene\Lucene.csproj">
+      <Project>{D5D447D7-EF8E-43A6-B9A4-3B025DD9F45D}</Project>
+      <Name>Lucene</Name>
+    </ProjectReference>
     <ProjectReference Include="..\Orchard.Web\Modules\Orchard.Indexing\Orchard.Indexing.csproj">
       <Project>{EA2B9121-EF54-40A6-A53E-6593C86EE696}</Project>
       <Name>Orchard.Indexing</Name>