MSI: Update Magento 2 core to support MSI

Author: RomaKis

app/code/Magento/ImportExport/Controller/Adminhtml/Import/Download.php

@@ -84,8 +84,8 @@ public function execute()
             /** @var \Magento\Backend\Model\View\Result\Redirect $resultRedirect */
             $this->messageManager->addErrorMessage(__('Incorrect file name.'));
 
-            return $this->getResultRedirect();        }
-
+            return $this->getResultRedirect();
+        }
         try {
             $fileContents = $this->sampleFileProvider->getFileContents($entityName);
         } catch (NoSuchEntityException $e) {

lib/internal/Magento/Framework/MultiDimensionalIndexer/IndexName.php

@@ -8,6 +8,7 @@
 namespace Magento\Framework\MultiDimensionalIndexer;
 
 use Magento\Framework\Exception\LocalizedException;
+use Magento\Framework\Phrase;
 
 /**
  * Index Name object
@@ -43,7 +44,7 @@ public function __construct(string $indexId, array $dimensions, Alias $alias)
         foreach ($dimensions as $dimension) {
             if (!$dimension instanceof Dimension) {
                 throw new LocalizedException(
-                    __('Dimension have to be instance of Dimension class.')
+                    new Phrase('Dimension have to be instance of Dimension class.')
                 );
             }
         }

lib/internal/Magento/Framework/MultiDimensionalIndexer/README.md

@@ -1,8 +1,9 @@
-A library for multi dimensional indexing processing
+The **\Magento\Framework\MultiDimensionalIndexer** library provides functionality of multi-dimension index creation and
+handling.
 
-it's supposed to split indexes by the Dimensional (Scope). Builds independent index table per each Dimensional. 
-Dimension and Alias objects help to resolve correct index.
+Library introduces a set of extension points which split monolithic index by specified Dimension (Scope), creating 
+independent index (i.e. dedicated MySQL table) per each Dimension. Along with that library provides index name 
+resolving mechanism based on provided scope. The Multi-Dimension indexes introduced for the sake of data scalability
+and ability to reindex data in the scope of particular Dimension only.
 
-Contains switchable indexes to switch from an old index (current index, which exists before full reindex operation 
-has been launched) to a new index (created when the full reindex operation finished) with zero downtime to make 
-Front-End responsive while Full Reindex being worked.
+Aliasing mechanism guarantees zero downtime to make Front-End responsive while Full Reindex being processed.