Robust, sanitised inputs

[Lord-Akkrand]

Currently there's no checks to make sure the scripts are getting what they expect.

• Some scripts expect a folder that is the "Data" folder, that is, it contains esps/bsas/ini/etc and/or the folders textures/meshes/interface/etc.
• Others expect a folder containing the "Data" folder.

Some basic checks and sanitisation would allow each script to work that out for itself.

Similarly, there's no check to see if the origin/target folders passed in are sane. If you were to pass in:
Origin=C:\blah\something\mod
Target=C:\blah
then ROBOCOPY would clobber your entire blah folder, and probably break all the things.

[Lord-Akkrand]

It's better now. All the conversion scripts take the same input, and there's no longer some scripts using base/Data/ whilst others use base/
Still need to give a warning or error out if your ROBOCOPY would clobber the origin.