minor, print an error message if files for muxing cannot be opened

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>
Merge branch 'tool/echse'

* tool/echse:
  minor, print an error message if files for muxing cannot be opened
test, provide regression for single EXDATE amongst dates of RRULE

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>
minor, sort exdates in rrule events before handing them over to make_evrrul()

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>
minor, actually exclude exdates from rrule cached rdates

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>
Merge branch 'core/evical-exdate'

* core/evical-exdate:
  minor, actually exclude exdates from rrule cached rdates
  minor, sort exdates in rrule events before handing them over to make_evrrul()
  test, provide regression for single EXDATE amongst dates of RRULE