Check that paths and additional modules exist
Check that paths and additional modules exist

- Moved the checkPath function to the top so it can be used right away,
also hide it's output
- Check that workingDir exists, if not tell them to configure the script
- Create the folders under workingDir
- Check that Convert-WindowsImage exists, and gets loaded properly. Also
tell them where to download and install it.
- Check that PSWindowsUpdate module exists, and tell them where to
download and install it.

mdragan/Virtualization-Documentation,timbodv/Virtualization-Documentation,mebersol/Virtualization-Documentation,enghch/Virtualization-Documentation