ytsm is now POSIX compliant.

ytsm is now POSIX compliant enough to run in dash, which performs much,
much better than bash. The README has been updated accordingly.

The README is now cron agnostic. The directions previously used @daily,
which works for vixie-cron, but not necessarily other daemons. 0 0 * * *
should be recognized by pretty much every cron daemon ever.
ytsm-cronjob now reads the real upload date

No more faking it with the current system date. This introduces a few
minor caveats, the biggest of which is that if a new video is for some
reason datestamped a month ago, it won't show up anywhere near the top
of the feed, much less among the new items. The other thing is that the
'today' feature is now essentially useless, as it is mostly replaced by
the 'new' feature in functionality. This will become a 'yesterday'
button that does what the old 'today' button did whenever I next have
time to work on it.

I've introduced some error checking for the new title/date mechanism. If
it doesn't detect the date from youtube-dl, it falls back on system
time. If yt-dl/ytsm can't get the title, it will substitute it for a
brief message telling us that there was a problem.

Also, I deliberately didn't disable the youtube-dl.conf because the
--get-thing options are supposedly simulations, which should skip most
undesirable actions like auto downloading or audio ripping.
today is now yesterday.

The today command is mostly functionally replaced by the yesterday
command. It now prints videos that are uploaded yesterday, or today if
one video uses the new fallback date method (which is the same as the
old method).

I also cleaned up a comment I missed in the POSIX update and added a
comment regarding the escape character that I thought I made but
apparently only went into the commit log.