Add first version of phishing site warning

Links to my own blacklist for now, since I added a package.json for easy importing.

We can point at the main 408H repository once this is merged:
https://github.com/409H/EtherAddressLookup/pull/24

Redirects detected phishing sites [here](https://metamask.io/phishing.html).

app/manifest.json

@@ -52,6 +52,12 @@
       ],
       "run_at": "document_start",
       "all_frames": true
+    },
+    {
+      "run_at": "document_end",
+      "matches": ["http://*/*", "https://*/*"],
+      "js": ["scripts/blacklister.js"],
+      "css": ["css/blacklister.css"]
     }
   ],
   "permissions": [

app/scripts/blacklister.js

@@ -0,0 +1,13 @@
+const blacklistedDomains = require('etheraddresslookup/blacklists/domains.json')
+
+function detectBlacklistedDomain() {
+  var strCurrentTab = window.location.hostname
+  if (blacklistedDomains && blacklistedDomains.includes(strCurrentTab)) {
+    window.location.href = 'https://metamask.io/phishing.html'
+  }
+}
+
+window.addEventListener('load', function() {
+  detectBlacklistedDomain()
+})
+

gulpfile.js

@@ -172,6 +172,7 @@ gulp.task('default', ['lint'], function () {
 const jsFiles = [
   'inpage',
   'contentscript',
+  'blacklister',
   'background',
   'popup',
 ]

package.json

@@ -68,6 +68,7 @@
     "eth-sig-util": "^1.1.1",
     "eth-simple-keyring": "^1.1.1",
     "eth-token-tracker": "^1.1.2",
+    "etheraddresslookup": "github:flyswatter/EtherAddressLookup#AddPackageJson",
     "ethereumjs-tx": "^1.3.0",
     "ethereumjs-util": "ethereumjs/ethereumjs-util#ac5d0908536b447083ea422b435da27f26615de9",
     "ethereumjs-wallet": "^0.6.0",