Log Message:
Update to 3.44. From the changelog:

- fixed gcc 8 compilation warnings
- fixed Ruby string interpolation
  (https://github.com/andre-simon/highlight/issues/70)
- added support for ALAN IF (thanks to Tristano Ajmone)
- added 107 Base16 themes [https://github.com/chriskempson/base16]
  (thanks to Tristano Ajmone)
- updated Rust and Java reserved words lists
- revised documentation
- moved extras/css-themes into extras/themes-resources
- added extras/themes-resources/base16 (thanks to Tristano Ajmone)
- GUI: added Base16 theme selection checkbox
- CLI: added --base16 option to enable the new themes
- CLI: accept - as argument to read from stdin
  (https://github.com/andre-simon/highlight/issues/73)