For #25587 - Spaces in Windows PC & Python paths are now supported.

Spaces are now supported in paths for Pipeline Configurations on Windows when using the latest version of the tank.bat file.  Additionally, Python can now be installed into a path with spaces in (e.g. C:\Program Files) if needed.
I am not suggesting that you add comments for every single detail Alan. That's ridiculous and if that's how my comment came across, I do apologise! However, trying to think pragmatically, here are my personal view: I have done a fair bit of win batch programming in my life. In fact, I wrote the original versions of these files. That doesn't mean I know all the parameters and all the little intricacies of batch syntax, (especially not stuff that has been added recently). I am not suggesting that you write an essay on batch programming here, but as a *helpful gesture* to a reader, perhaps include this link in a comment:

http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/for.mspx?mfr=true

That's one very useful line that would let me jump straight to the relevant documentation - if I for some reason wanted to know more about `usebackq tokens=*` means. So what I suggest is:

```
rem -- for additional syntax details see 
rem -- http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/for.mspx?mfr=true
```

Do you think that is overkill?