Post thumbnail will be selected randomly if no file is given. If a file is given, but it's invalid, it should(but doesn't) raise an exception. Tristin will work on the actual exception handling, since he's been doing all the complicated form stuff.
multiupload now includes subfolder string in name. Makes it easier to set thumbnail
Merge branch 'thumbnailrework' of https://github.com/traverseda/Django3Dtools into thumbnailrework

Conflicts:
	post/models.py