#665 support multiple open files with the same basename. Always clean up backups on window close
Inspired by #386, delete main windows on close
proper quotation of \" special case
Merge pull request #668 from tim-caper/master

proper quotation of \" special case
Added fixme for release builds
Print error message if upload fails
Merge branch 'master' of github.com:openscad/openscad
Enable experimental features only for snapshot builds
Updated RELEASE NOTES