Overview of changes in gcalctool 5.29.92

    * Add shortcuts to base buttons (Ctrl+B, Ctrl+O, Ctrl+D, Ctrl+H)

    * Convert number in display if it has a base and a base button is pressed

    * Make scientific notation button behave the same as keyboard shortcut (i.e.
      go into superscript mode).
      
    * Only allow superscript minus to be entered if can make a valid superscript
      number, otherwise revert to standard minus.

    * Allow hexadecimal numbers to be entered in lower-case

    * Make bit editor active for displayed numbers not in base 10

    * Make variable powers work, e.g. x²

    * Fix spacebar not working when display has focus (Bug #611971)

    * Load currency rates when doing typed currency conversion
    
    * Use GIO instead of libsoup