MAGETWO-65208: Store checksum for every section of configuration file & change behavior on read-only FS & add sorting of importers

Author: Bohdan Korablov

app/code/Magento/Deploy/Console/Command/App/ConfigImport/Importer.php

@@ -80,7 +80,7 @@ public function __construct(
      *
      * @param OutputInterface $output the CLI output
      * @return void
-     * @throws LocalizedException
+     * @throws LocalizedException is thrown when import has failed
      */
     public function import(OutputInterface $output)
     {

app/code/Magento/Deploy/Model/DeploymentConfig/Hash.php

@@ -70,7 +70,10 @@ public function __construct(
     /**
      * Updates hash in the storage.
      *
-     * @param string $sectionName
+     * If the specific section name is set, then hash will be updated only for this section,
+     * in another case hash will be updated for all sections which defined in di.xml
+     *
+     * @param string $sectionName the specific section name
      * @return void
      * @throws LocalizedException is thrown when hash is not saved in a storage
      */