add WARN is db version is old

lib/HistoricSync.js

@@ -334,6 +334,15 @@ HistoricSync.prototype.prepareToSync = function(opts, next) {
 
   self.status = 'starting';
   async.series([
+    function(s_c) {
+      self.sync.txDb.checkVersion02(function(isV02){
+        if (!isV02) {
+          console.log('\n#############################\n\n ## Insight API DB is older that v0.2. Please resync using:\n $ util/sync.js -D\n More information at Insight API\'s Readme.md')
+          process.exit(1);
+        }
+        return s_c();
+      });
+    },
     function(s_c) {
       self.checkNetworkSettings(s_c);
     },

lib/TransactionDb.js

@@ -671,4 +671,13 @@ TransactionDb.prototype.getPoolInfo = function(txid, cb) {
   });
 };
 
+
+TransactionDb.prototype.checkVersion02 = function(cb) {
+  var k = 'txb-f0315ffc38709d70ad5647e22048358dd3745f3ce3874223c80a7c92fab0c8ba-00000000b873e79784647a6c82962c70d228557d24a747ea4d1b8bbe878e1206';
+  db.get(k, function(err, val) {
+    return cb(val? false : true);
+  });
+};
+
+
 module.exports = require('soop')(TransactionDb);