WebSocket real-time updates: faster polling + network events

- Reduce polling interval to 5 seconds for faster updates
- Add network update events (peer count changes)
- Include block type (PoS/PoW) in newBlock events
- Track connected WebSocket clients
- Emit networkUpdate when peer count changes

This enables real-time live feed on the explorer frontend.

node_modules/base64id/package.json

@@ -0,0 +1,13 @@
+{
+    "name": "base64id"
+  , "version": "2.0.0"
+  , "license": "MIT"
+  , "description": "Generates a base64 id"
+  , "author": "Kristian Faeldt <faeldt_kristian@cyberagent.co.jp>"
+  , "repository": {
+        "type": "git"
+      , "url": "https://github.com/faeldt/base64id.git"
+   }
+  , "main": "./lib/base64id.js"
+  , "engines": { "node": "^4.5.0 || >= 5.9" }
+}