Initial Version of a NSIS installer script
- Multi-user install (install for just one or all)
- Registers uninstaller (more values need to finish up)
- Tested both single and all install / uninstall and works
- Still need to add parameters instead of hardcoded values in some spots
- Need to clean up vendor folders / keys if empty on uninstall
- Need to add the other dupeGuru languages to the language list
- Minor cleanup of script needed as well
Ref #393
