Issue 2375 - Implement "Blocking lists" section in new options page

locale/en-US/options.json

 {
   "options_page_title": {
     "description": "Options page title",
     "message": "Adblock Plus Options"
   },
   "options_page_header_1": {
     "description": "Page title in navigation sidebar",
     "message": "Options"
   },
   "options_page_header_2": {
@@ skipping 127 matching lines @@
   "options_tweaks_title": {
     "description": "Section title in Advanced tab",
     "message": "Tweaks"
   },
   "options_tweaks_blockElement": {
     "description": "Show block Element option in Advanced tab",
     "message": "Show <a>Block Element</a> right-click menu item"
   },
   "options_filterList_title": {
     "description": "Section title in Advanced tab",
-    "message": "Filter list"
+    "message": "Filter lists"
   },
   "options_tab_overview": {
     "description": "Tab name in Advanced tab",
     "message": "Overview"
   },
   "options_tab_ownList": {
     "description": "Tab name in Advanced tab",
     "message": "Edit or create own filter list"
   },
   "options_column_name": {
     "description": "Name of column of subscription list table in Advanced tab",
     "message": "Name"
   },
   "options_column_date": {
     "description": "Name of column of subscription list table in Advanced tab",
     "message": "Last update"
   },
   "options_filterList_add": {
     "description": "Import button in Advanced tab",
     "message": "add/import other filter list"
   },
   "options_filterList_update": {
     "description": "Update button in Advanced tab",
     "message": "update all filter lists"
   },
   "options_customFilters_empty": {
     "description": "Text shown when list of custom filters is empty",
     "message": "There are no custom filters."
   },
-  "options_subscription_lastDownload_invalidURL": {
+  "options_filterList_lastDownload_invalidURL": {
     "description": "Error message in advanced tab",
     "message": "Failed, not a valid address"
   },
-  "options_subscription_lastDownload_connectionError": {
+  "options_filterList_lastDownload_connectionError": {
     "description": "Error message in advanced tab",
     "message": "Failed, download failure"
   },
-  "options_subscription_lastDownload_invalidData": {
+  "options_filterList_lastDownload_invalidData": {
     "description": "Error message in advanced tab",
     "message": "Failed, not a valid filter list"
   },
-  "options_subscription_lastDownload_checksumMismatch": {
+  "options_filterList_lastDownload_checksumMismatch": {
     "description": "Error message in advanced tab",
     "message": "Failed, checksum mismatch"
+  },
+  "options_filterList_lastDownload_inProgress": {
+    "description": "Progress message in advanced tab",
+    "message": "Downloading…"
   },
   "options_filterList_updateNow": {
     "description": "Context menu item in advanced tab, appears after click on subscription",
     "message": "update now"
   },
   "options_filterList_website": {
     "description": "Context menu item in advanced tab, appears after click on subscription",
     "message": "website"
   },
   "options_filterList_source": {
@@ skipping 170 matching lines @@
   },
   "options_language_ro": {
     "description": "Language name shown in add language modal dialog",
     "message": "Romanian"
   },
   "options_language_ru_uk": {
     "description": "Language name shown in add language modal dialog",
     "message": "Russian and Ukrainian"
   }
 }