Add support for i18n
This setups biboumi for future internationalisation using gettext and libintl.
This commit adds support in:
- CMake, making the two Intl and Gettext packages required, used to compile .po files into .mo files and putting them in the correct location once installed.
- Custom scripts, scripts/update_pot.sh needs to be called whenever you want to synchronise the C++ files strings into the .pot template, and scripts/merge_po.sh, when you want to merge the .pot and existing translations.
- main.cpp, setting up the locale and the text domain.
What remains is to litter the code of _(…) on every string you want translated, running scripts/update_pot.sh, copying po/biboumi.pot to po/.po, and start translating it.