2) Don't allow to add new networks/implement existing ones for VPC in Disabled state. Disabled state indicates that there was unsuccessful attempt to remove the VPC, and the further cleanup will be taken care of by cleanup thread.
Conflicts:
server/src/com/cloud/network/dao/IPAddressDao.java
server/src/com/cloud/server/ManagementServerImpl.java
2) Added services api support for plugging/unplugging the nics to VpcElement
Conflicts:
api/src/com/cloud/network/NetworkService.java
core/src/com/cloud/vm/VMInstanceVO.java
server/src/com/cloud/network/NetworkManagerImpl.java
server/src/com/cloud/network/router/VirtualNetworkApplianceManagerImpl.java
server/test/com/cloud/network/MockNetworkManagerImpl.java