[Cin] Backup up your EDL when use latest build

Latest GIT checkin addressed some outstanding labels/auto/keyframes follow edits in cut and paste mode and drag and drop mode. I could not find the appropriate MantisBT issue to file this under. The closest I could find was #100 but I think there was email from IgorB about an outstanding label problem still. This was somewhat hard to test here so suggesting you backup your EDL before you use this latest build until you are comfortable with it. There is a new Ubuntu16 and Mint 18 build. Thank you, gg/phyllis https://www.cinelerra-gg.org/download/testing/cinelerra-5.1-ub16-x86_64-stat... https://www.cinelerra-gg.org/download/testing/cinelerra-5.1-mint18-x86_64-st...