Update to 3.3.52
    
    - New upstream release 3.3.52
      - Added LZ4 as compression type for FST; when enabled with --fourpack in
        vcd2fst, this compresses both signal data and the hierarchy using LZ4
      - Added WLF support via wlf2vcd; to use, specify -o at the command line
        (e.g., gtkwave -o test.wlf)
      - Changed left/right arrow function in signal/wave windows to find next
        transition of selected signal(s)
      - Re-enabled DnD scroll beyond top/bottom of Signals pane
      - Added debounce for baseline (middle) mouse button
      - Another partial VCD loader fix
      - Now use libcomdlg32 file requesters on MinGW
      - Added --extensions flag to fstvcd to enable emission of FST extensions/
        attributes to VCD files; this is to keep FST attributes from making VCD
        files unparseable with other tools
      - Fix in FsdbReader interface for version 1.x files
      - Many warnings fixes found from gcc -Wextra flag
      - Fixed thread-unsafe static allocations in fstapi.c