fix #308: Creating a new .NET 4.5.1 project results in a .NET 4.0 project

Author: siegfriedpammer

src/Main/SharpDevelop/Templates/Project/ProjectDescriptor.cs

@@ -306,6 +306,7 @@ public bool CreateProject(ProjectTemplateResult templateResults, string defaultL
 				Directory.CreateDirectory(projectBasePath);
 				FileName projectLocation = projectBasePath.CombineFile(newProjectName + descriptor.ProjectFileExtension);
 				ProjectCreateInformation info = new ProjectCreateInformation(parentSolution, projectLocation);
+				info.TargetFramework = projectCreateOptions.TargetFramework;
 
 				StringBuilder standardNamespace = new StringBuilder();
 				// filter 'illegal' chars from standard namespace