This adds require("_date") to some example tests that use the current
date via os.date. This allows reproducibility by replacing os.date()
with a function that uses a static date from $SOURCE_DATE_EPOCH. See
commit 9d7eaf0 for more details.
Signed-off-by: Uli Schlachter <psychon@znc.in>
It also add some properties such as `border_width`, `border_color`
and `preferred_alignments`.
It also fix a documentation bug where the `margin_topleft` was called
`margins_topleft`. To conform to the documentation, both are now valid
but one should be removed the next time the API changes.
Fixes#1978