Remove trailing "blank" lines in source files.

I like to use global-whitespace-cleanup-mode, but I can not use it if the files are "dirty" to begin with. This fix will make more files "clean". I also considered adding a check for this in jcheck for skara, however it seems jcheck code handling hunks does not track end-of-files.

The fix removes trailing lines matching ^[[:space:]]*$ in
*.java
*.cpp
*.hpp
*.c
*.h