- allow msi major upgrade
- add desktop and start menu shortcut for mbackup.exe file
- set HOME env variable when running rsync.exe.
  ssh.exe wants to access HOME dir.
  but this change seems not working in win 10 VM.
- add Version info in mbackup.fsproj
  - mbackup.exe supports --version option.
    - when build msi file, include version in filename
    - use printf %A to print exception detail.