minor, allow multiple selectors in echs_select()

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, provide rename builder to rename state names on the fly

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, provide control funs for echs_select() and echs_rename() streams

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, use echs_rename() and echs_select() in its multi-variant for de holiday list

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, provide control function (shallow though) with CLONE and UNCLONE for mux streams

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, put default's in all switches in builders.c

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, fix __wday_before() filter, echs_instant_fixup() cannot be used

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, provide uk holidays DSO for proof-of-concept purposes re echs builders

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'feat/builders' into next

* feat/builders:
  minor, provide uk holidays DSO for proof-of-concept purposes re echs builders
  minor, fix __wday_before() filter, echs_instant_fixup() cannot be used
  hygiene, put default's in all switches in builders.c
  minor, provide control function (shallow though) with CLONE and UNCLONE for mux streams
  minor, use echs_rename() and echs_select() in its multi-variant for de holiday list
  minor, provide control funs for echs_select() and echs_rename() streams
  minor, provide rename builder to rename state names on the fly
  minor, allow multiple selectors in echs_select()