Update to Opal

As I mentioned, I am using the new clang compiler and LLVM back end in the latest update (version 1.2.5) to my Opal outliner. I couldn’t really detect any differences in performance, but I’ll take the faster compiles!

The clang code analyzer did find a number of minor memory leaks, mostly in things that are less common, like printing or using the bookmark popup. So this release is cleaner than ever.