Fixing Windows not playing nicely with mkdir.

[nitz]

I really don't know why Windows is such a pain sometimes:

• The -p doesn't get handled as a switch, and instead actually creates a directory named "-p"...
• The forward slash in the path being created causes cmd.exe to be sad instead of interpreting it as a path. Quotes around the path makes it happy.

One day things will be sane on Windows.

Today is not that day. 😂