Added batch mode to chocolatey.cmd - cinst multiple packages

I wrote this batch installer.

It's a small clever hack I wrote some time ago for myself. But now that I installed Chocolatey on a friend's computer, I realized how much I missed this invaluable feature, so I thought I'd put it in a pull request.

Everything remains the same, but you can now also do this:
```cmd
cinst notepadplusplus 7zip vlc putty GoogleChrome firefox filezilla adobereader Skype Dropbox VirtualCloneDrive foobar2000 gimp pidgin xnview speccy opera xnview
```
..and go drink a cofffee. :)