Updated mset9.bat to Install Python

[J0n-b0]

Rather than telling Windows users to install Python themselves, I've updated the .bat to do it for them. This has not been tested on Windows 7, but unless i did something wrong it should work.

It does the following:

• Checks if python or py exists, and runs them it they do (fixes Check for both "py" and "python" commands on Windows #33)
• If not found, it asks user if they want to install Python
• If yes, it downloads and installs the appropriate Python version (based on their Windows version) and opens and runs mset9.py in a new cmd instance

This hopefully will cut out the middleman of users downloading Python themselves, which some users can get confused on.

[J0n-b0]

Forgot to add event if windows version not supported, will add