Automatically integrate CREGFIX into the QuickInstall setup

[rawr51919]

There are two possible ways of integrating CREGFIX into Win98 QuickInstall:
• Current way of doing this: Make users manually use the floppy or integrate it themselves
• Automatically detect the CPU instructions used and have it copied in automatically at the end of setup

A third would be making reference images that have CREGFIX integrated on them already which was dismissed as being too hellish to maintain which is understandable

This seems to have been an issue for QuickInstall for a while now, issue made to help creator keep track of this

[rawr51919]

PR #47 fixes this issue by installing and then preparing AUTOEXEC.BAT for CREGFIX the same way any user would manually do it for any other installation. This works because of the way win9x-quickinstall install media works, similarly to that of Windows Longhorn beta install media.