setting of SCHEDULED:  and DEADLINE: Keywords

heading.scheduled_date, heading.closed_date and heading.deadline_date should
always be of OrgDate (or OrgDateTime) type.

according to
https://orgmode.org/worg/dev/org-syntax.html#Timestamp

the dayname field can be pretty much anything. And indeed in german
locale setting the dayname is abbreviated with 2 letters only

also make the mappings somewhat easier to remember by having the p in
front mean calendar selection and having the s in front does mean cmdline
 selection.

Manage the Plannings-Line CLOSING: Keyword
When the TODO State changes from Done to not Done or vice versa

so the fix is, that we save a list of matches instead of a reference to the iterator

The line=None case was broken. It turns out, that it works better,
if line is empty string per default.

We do test heading parsing and not date-time parsing, so these cases should be enough.

Sorting should ignore inactive dates -> test added.

according to:
https://orgmode.org/worg/dev/org-syntax.org.html

there are only a few restrictions on the DAYNAME part. (Which is wise for other locales).
So <2011-08-29 mon> is a valid date.

…eiving end

Allow missing day, because it is a reasonable human readable date form and we should probably brake no viable usecases with this.

According to current formulation of the timestamp spec, a Date without Time is not valid anyway.

-> pt_br Locale day-names were changed to lowercase letters in this commit:
https://sourceware.org/git/?p=glibc.git;a=commit;h=686db256f640372df81242bf20d458f54e069f56

The pt_BR locale had the weekday capitalization changed [1]. That means that depending on libc version (-> Travis build tests vs Fedora 29) the test either was successull or failed [2].

[1]: https://sourceware.org/git/?p=glibc.git;a=commit;h=686db256f640372df81242bf20d458f54e069f56
[2]: commit e05f4f3

re commit e05f4f3