Examine source code of firewall

{
  "manifest_version": 2,
  "name": "firewall",
  "version": "1.1.1resigned1",
  "author": "Jirka Justra",
  "description": "[č]Allows website requests filtering and header alteration --- icon from: Martz90 http://martz90.deviantart.com/art/Hex-Icons-Pack-389706981",
  "applications": {
    "gecko": {
      "id": "firewall@example.com"
    }
  },
  "icons": {
    "16": "icons/16.png",
    "24": "icons/24.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "64": "icons/64.png",
    "72": "icons/72.png",
    "96": "icons/96.png",
    "128": "icons/128.png",
    "256": "icons/256.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "icons/16.png",
      "24": "icons/24.png",
      "32": "icons/32.png",
      "48": "icons/48.png",
      "64": "icons/64.png",
      "72": "icons/72.png",
      "96": "icons/96.png",
      "128": "icons/128.png",
      "256": "icons/256.png"
    },
    "default_title": "todo: counter",
    "default_popup": "popup.html",
    "browser_style": false
  },
  "permissions": [
    "storage",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "./lib/hshlib.js",
      "./lib/hshlib_std.js",
      "./lib/hshlib_std_core.js",
      "./lib/hshlib_std_tools.js",
      "./lib/hshlib_std_coders.js",
      "./lib/hshlib_firewall.js",
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  }
}