stub for the VMBackup.

stub for the VMBackup.
code to freeze the file system

first, find the mounted file systems then freeze the file system, then
do the snapshot, then unfreeze the file system.
some ignorance of the files would be fetched by the setup.py, and basic code for doing the snapshot using the sas uri.

some ignorance of the files would be fetched by the setup.py, and basic
code for doing the snapshot using the sas uri.
make the stub script and fix the system freezed bug.

make the stub script and fix the system freezed bug.