bitmapview.c backwards compatibility with older libuninameslist

Right now, the current FontForge is stripped from old libuninnames library access, so to test this one fix, you will need to use the current "latest" update that includes 2 functions in it at https://github.com/fontforge/libuninameslist.

If you want to try the old and new branch, just change the #ifndef into #ifdef to try the "other" branch. To differentiate which branch you follow, I suggest changing the three strcat(buf, " "); into: strcat(buf, "A"); strcat(buf, "B"); strcat(buf, "C"); so that you can tell them apart during checking for mainstream acceptance.

Other routines still need to be modified first before FontForge can accept an older libuninameslist