DNS records for additional local IP addresses

##### ISSUE TYPE
* Feature Idea

##### COMPONENT NAME
* DNS

##### CLOUDSTACK VERSION
/

##### CONFIGURATION
* for customer isolated network

##### OS / ENVIRONMENT
/

##### SUMMARY
For adaptive computing it's important to get use of additional application local IP addresses which you can move between machines in case of a failure of one of the virtual machines or for upgrades.

I can attach an additional IP to a VM using ACS. But I cannot give that a separate name which does not belong to the actual hostname of the VM.

##### STEPS TO REPRODUCE

##### EXPECTED RESULTS
* possibility to add a DNS name for the additional local IP address
* possibility to move an IP from one system to another (no delete and recreate - IP could be taken in the steps between)

##### ACTUAL RESULTS
* currently the additional IP resolves into the same name as the original IP which is the hostname

从 CloudStack DNS 组件开始，追踪当前额外的本地 IP 地址如何解析到 VM 的主机名。定义如何分配一个独立的 DNS 名称，以及如何在不删除和重新创建的情况下将 IP 在虚拟机之间移动；当两个预期结果都能在隔离的客户网络中正常工作时，即视为完成。

由索引模型根据 Issue 内容生成。