add user defined blacklist

Moving some of the previously blacklisted sites to user controlled
blacklist. Remaining sites in manifest are blocked due to interop
issues.

Closes #121.

manifest.json

@@ -1,7 +1,7 @@
 {
   "name": "Video Speed Controller",
   "short_name": "videospeed",
-  "version": "0.3.1",
+  "version": "0.3.3",
   "manifest_version": 2,
   "description": "Speed up, slow down, advance and rewind any HTML5 video with quick shortcuts.",
   "homepage_url": "https://github.com/igrigorik/videospeed",
@@ -22,16 +22,13 @@
   },
   "content_scripts": [{
       "all_frames": true,
-      "matches": [ "http://*/*", "https://*/*", "file:///*"],
+      "matches": [ "http://*/*", "https://*/*", "file:///*" ],
       "exclude_matches": [
         "https://plus.google.com/hangouts/*",
         "https://hangouts.google.com/hangouts/*",
         "https://teamtreehouse.com/*",
-        "https://www.instagram.com/*",
-        "https://www.twitter.com/*",
         "https://www.lynda.com/*",
-        "http://www.hitbox.tv/*",
-        "https://vine.co/*"
+        "http://www.hitbox.tv/*"
       ],
       "css": [ "inject.css" ],
       "js":  [ "inject.js" ]