Overview of changes in gnome-calculator 3.15.4
    * New : Keyboard mode (Elita Lobo)
    * New : MPFR back-end (Daniel Renninghoff)
    * New : Digital Storage conversion (PioneerAxon)
    * Update : Switch to GPLv3+ license (Michael Catanzaro)
    * Update : Case-insensitive conversion units (PioneerAxon)
    * Update : Don't copy thousand separators to clipboard (PioneerAxon)
    * Update : Translations (Translation team)
    * Fix : Use HTTPS for downloading exchange rates (Michael Catanzaro)
    * Fix : Repeated entries in history view (Elita Lobo)
    * Fix : Padding in UI buttons (Trinh Anh Ngoc)
    * Fix : Style history view boarder (Trinh Anh Ngoc)
    * Fix : Sort currencies based on locale (Lubomír Sedlář)
    * Fix : Deprecated use-stock property (David King)
    * Fix : Download missing exchange rates on first launch (PioneerAxon)
    * Fix : Missing buildtime dependency (Emmanuele Bassi)
    * Fix : gtksourceview binding change (Michael Catanzaro)