minor, split ddiff specifier docs into the actual specifiers and the refinement rule

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, explicitly list all possible refinements

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
doc, cosmetics, align format.texi and format-ddiff.texi

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'doc/format-specs'

* doc/format-specs:
  doc, cosmetics, align format.texi and format-ddiff.texi
  minor, explicitly list all possible refinements
  minor, split ddiff specifier docs into the actual specifiers and the refinement rule
minor, provide ui32topstr() to allow for arbitrary padding chars

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, pad output with spaces if %SPC modifier is present

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Revert "minor, pad output with spaces if %SPC modifier is present"

This reverts commit baea2adbf1f75f0bcc7e508668f1e053403dffe0.

This would slow down dconv by ~12% for no apparent gain.
Merge branch 'feat/SPC-modifier'

* feat/SPC-modifier:
  Revert "minor, pad output with spaces if %SPC modifier is present"
  minor, pad output with spaces if %SPC modifier is present
  minor, provide ui32topstr() to allow for arbitrary padding chars
minor, provide __ywd_diff() for ISO week-year calendar differences

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, support ISO week-year differences in dt_ddiff()

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, support iso week-day differences in ddiff(1)

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
test, add regressions for year-week differences

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, PEBKAC, actually compute the difference between d2 and d1

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
test, fix PEBKAC, output actual values for ddiff.055.clit

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, PEBKAC, actually determine the number of isoweeks in a year (not a difference of years)

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
test, add regressions for isoweek carry-over

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'feat/year-week-refinement'

* feat/year-week-refinement:
  test, add regressions for isoweek carry-over
  fix, PEBKAC, actually determine the number of isoweeks in a year (not a difference of years)
  test, fix PEBKAC, output actual values for ddiff.055.clit
  fix, PEBKAC, actually compute the difference between d2 and d1
  test, add regressions for year-week differences
  minor, support iso week-day differences in ddiff(1)
  minor, support ISO week-year differences in dt_ddiff()
  minor, provide __ywd_diff() for ISO week-year calendar differences
doc, list refinement of %Y through %w in format-ddiff.texi

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
doc, clarify that in a chain of refinements inner elements are optional

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'feat/year-week-refinement'

* feat/year-week-refinement:
  doc, clarify that in a chain of refinements inner elements are optional
  doc, list refinement of %Y through %w in format-ddiff.texi