Detailed cleanup of documentation blocks for spacing, language, placement, etc.

core/includes/bootstrap.inc

core/includes/install.core.inc

core/lib/Drupal/Core/ContentNegotiation.php

core/lib/Drupal/Core/Database/Connection.php

core/lib/Drupal/Core/DrupalKernel.php

core/lib/Drupal/Core/EventSubscriber/AccessSubscriber.php

.../Drupal/Core/EventSubscriber/FinishResponseSubscriber.php

...Drupal/Core/EventSubscriber/MaintenanceModeSubscriber.php

core/lib/Drupal/Core/EventSubscriber/PathListenerBase.php

core/lib/Drupal/Core/EventSubscriber/PathSubscriber.php

...ib/Drupal/Core/EventSubscriber/RequestCloseSubscriber.php

core/lib/Drupal/Core/EventSubscriber/RouterListener.php

core/lib/Drupal/Core/EventSubscriber/ViewSubscriber.php

core/lib/Drupal/Core/ExceptionController.php

core/lib/Drupal/Core/UrlMatcher.php

index.php