Yep. All you need is the .mpr file.
To make sure of that, create a new empty folder somewhere, copy the .mpr file to it and then doubleclick it. (Allthough I tried that twice now, both times resulting in empty javascriptsource, javasource, userlib, widget-libraries).
Those look like SVN revision files. You get them when you merge and there are conflicts.
https://tortoisesvn.net/docs/release/TortoiseSVN_en/tsvn-dug-conflicts.html
If you’ve resolved the conflicts they should be safe to remove.