Binary and decimal modes are supported (MB and MiB ie.)
It supports i18n using gettext and locale.
Precision can be modified if needed, by default it is using 1 digit (if needed).
Extensive tests were written, the toughest was to make them work for
both default C locale and fr_FR.UTF-8 locale (ofc it is possible to test for more
locales...). If one locale isn't available on testing system, test is skipped.
fr locale was chosen because decimal point is replaced by a comma and byte units
becomes "octet" units (1.5 MB in english -> 1,5 Mo in french).
Fixes an issue from the previous commit where I used _ as a temp
variable name. It only broke the infodialog, but I'm replacing it
everywhere just to be safe.
