Fixed major error when restoring package via MSBuild after 4b61116

```
msbuild ClassLibrary1.sln /t:Build
```

It was because of unevaluated value from imported nodes. For clarify, it should be evaluated in first build step, then MSBuild will cache this evaluated values (ref~ `<prjfile>.CoreCompileInputs.cache`), then it will work fine (i.e. only for second builds).

No problems for local scope, but it also can be like:

```
DllExport -action Restore & msbuild ClassLibrary1.sln /t:Build
```

Well, this commit just avoids global scope in `Reference` item.

+Also fixed DXP_PE_CHECK for allocator.

Wizard/MSBuildProperties.cs

@@ -28,6 +28,11 @@ public struct MSBuildProperties
     {
         public const string DXP_ID = "DllExportIdent";
 
+        /// <summary>
+        /// Meta library file name.
+        /// </summary>
+        public const string DXP_METALIB_NAME = "DllExportMetaLibName";
+
         /// <summary>
         /// https://github.com/3F/DllExport/issues/2
         /// </summary>

Wizard/Project.cs

@@ -205,6 +205,7 @@ public Project(IXProject xproject, IConfigInitializer init)
 
             AllocateProperties(
                 MSBuildProperties.DXP_ID,
+                MSBuildProperties.DXP_METALIB_NAME,
                 MSBuildProperties.DXP_NAMESPACE,
                 MSBuildProperties.DXP_ORDINALS_BASE,
                 MSBuildProperties.DXP_SKIP_ANYCPU,
@@ -214,6 +215,7 @@ public Project(IXProject xproject, IConfigInitializer init)
                 MSBuildProperties.DXP_CUSTOM_ILASM,
                 MSBuildProperties.DXP_INTERMEDIATE_FILES,
                 MSBuildProperties.DXP_TIMEOUT,
+                MSBuildProperties.DXP_PE_CHECK,
                 MSBuildProperties.PRJ_PLATFORM
             );
 
@@ -324,6 +326,7 @@ protected void CfgNamespace()
         {
             CfgDDNS();
 
+            SetProperty(MSBuildProperties.DXP_METALIB_NAME, UserConfig.METALIB_NAME);
             SetProperty(MSBuildProperties.DXP_NAMESPACE, Config.Namespace ?? String.Empty);
             SetProperty(MSBuildProperties.DXP_DDNS_CECIL, Config.UseCecil);
         }

Wizard/UserConfig.cs

@@ -39,6 +39,11 @@ public class UserConfig: IUserConfig
         /// </summary>
         public const string NS_DEFAULT_VALUE = "System.Runtime.InteropServices";
 
+        /// <summary>
+        /// Default meta library.
+        /// </summary>
+        public const string METALIB_NAME = "DllExport.dll";
+
         /// <summary>
         /// Flag of installation.
         /// </summary>