major, turn dt-io.h convenience header into libdutio.a

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, don't include implementation in header

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, give up DECLF magic in leaps.h

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, provide declarative header for leapseconds.def

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
chore, make ltrcc emit inclusion of leapseconds.h header

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, don't include implementation in header (tzraw.h)

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, give up DECLF magic in tzraw.h

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, use leapseconds definitions decl'd via leapseconds.h in tzraw.c

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, don't include implementation in header (dt-core.h)

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, don't include implementation in header (date-core.h)

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, don't include implementation in header (time-core.h)

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, give up DECLF magic in time-core.h

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
chore, include config.h in time-core.c

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, don't include token.c and strops.c in time-core.c but their header counterparts

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
chore, move __secs_since_midnight() inline to time-core.h

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, give up DECLF magic in date-core.h

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, don't include token.c and strops.c in date-core.c but their header counterparts

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
chore, build date-core and time-core objects of their own for libdut.a

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, give up DECLF magic in dt-core.h

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, export nleaps as the total number of leap transitions

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>