Add autodesk Modeling software formats

[Virtualchronos]

Hello !

Thanks for your huge improvement in such short time !

I'm using manyfold for storing my STL designs and i would also love to store their Autodesk format models so i won't have to search through tousand of files and folders when needed.

thoses files extensions are :

.ipt .iam (Autodesk Inventor wich i'm hugely using)
.f3d (Autodesk fusion) i'm not using it but a lot of people use it
.dwg (autocad) not using it much but i'ts hugely spreaded on many websites

I don't care to have image previews (it can be implemented by retrieving the base64 image string in the file) but I really need to at least have the files in the manyfold browser.
A huge plus would be to implement a place where to specify the extensions files names wich need to appear or be inside the model page.