编写VirtualMachines模块中的5个自动化用例及数据文件

MigrateVm_AutoSelectHost、MigrateVm_HandSelectHost、MigrateVm_OnlyOneHost、MigrateVm_NotAllowMigration、CancelMigration_DuringMigration
Merge remote-tracking branch 'origin/master'

Conflicts:
	src/TestCases/VirtualMachines.py