Re: [Cin] Checked in tweaked patches from Andrew - EXR, PNG, and TIFF

Andrew:

Also, minor bug:

If I render OpenEXR sequence, load it, play it, and then delete main image files but NOT index *.exrs - and try to load file from "recent files" sub-menu in main menu - Cin will terminate

Easily reproduced here. GG says OpenExr is doing a "throw" and Cinelerra normally does not "catch". This would be the very first "catch" in Cinelerra if it would be added and that is not the way gg wants to go unless we absolutely have to. This requires the error handling characteristics of the C++ runtime library. If you do that same thing with a TIFF sequence, it passes the error correctly back to Cinelerra to field instead of crash.