Add SetPermissions/PermsSynced/AllowedPublishSubjects/AllowedSubscribeSubjects/AccountName
to LeafConnection, and SendPermsAndAccountInfo/InitLeafNodeSmapAndSendSubs/GetPermSyncStatus
plus LeafPermSyncResult to LeafNodeManager. Add OnConnectionRegistered internal callback for
test synchronization. 10 new unit tests in LeafPermissionSyncTests.cs all passing.
