- avoid rounding minutes
- round the seconds taken in the card info screen
- provide different precise and imprecise modes, since we need
to display seconds to multiple decimals in some areas
- all .ftl files for a language are concatenated into a single file
at build time
- all languages are included in the binary
- external ftl files placed in the ftl folder can override the
built-in definitions
- constants are automatically generated for each string key
- dropped the separate StringsGroup enum
- drop the '5m3s' special casing done in the card stats screen, and
just use decimals
- change alignment of the review log so that the non-abbreviated
spans are easier to read
