move static isValid next to instance isValid

...to be easier for developers to parse and distinguish

lib/address.js

@@ -10,15 +10,6 @@ function Address(obj) {
     this.set(obj);
 };
 
-Address.isValid = function(addrstr) {
-  try {
-    var address = new Address().fromString(addrstr);
-  } catch (e) {
-    return false;
-  }
-  return address.isValid();
-};
-
 Address.prototype.set = function(obj) {
   this.hashbuf = obj.hashbuf || this.hashbuf || null;
   this.networkstr = obj.networkstr || this.networkstr || 'mainnet';
@@ -60,6 +51,15 @@ Address.prototype.fromString = function(str) {
   return this;
 }
 
+Address.isValid = function(addrstr) {
+  try {
+    var address = new Address().fromString(addrstr);
+  } catch (e) {
+    return false;
+  }
+  return address.isValid();
+};
+
 Address.prototype.isValid = function() {
   try {
     this.validate();