dwvsh is licensed under the BSD 2 Clause license.

This patch adds a cursory man page for the dwvsh binary.

Sort the output of the built-in 'export' and 'alias' commands, in cases
where all environment variables/aliases are printed out.

This patches fixes a bug, where sometimes, when a Rune::String was
detected, the resulting string from the string!() macro wasn't getting
pushed to the current verse.

Previously, the recite() function created the 'out' variable, which was
a String, that got passed to the various incant functions, in order to
capture STDOUT in certain situations. In cases where STDOUT was
captured, it was first converted to a String, and then appended to the
'out' variable, by means of String::from_utf8_lossy(). This works for
basic text, however, does NOT work for binary data. This becomes
problematic, when for example, downling a tar file with curl/wget, that
is then piped ('|') to the tar program. Using from_utf8_lossy() in this
case can corrupt the tar file. This patch makes it so that out is stored
as bytes by default, and only converted to a String when necessary.

Instead of handling aliases in the recite() function, which requires two
loops to handle properly with the current implementation, offload
checking for aliases to the read() function.

The `which` command is not necessarily a builtin, however, it can
display shell aliases. This patch adds a line into dist/etc/dwvshrc,
which allows /usr/bin/which to detect our shell aliases, and print them.

Make sure to interpret alias values as their own poems, since aliases
can be fairly complex.

Add documentation for anthology::lookup(), with a list containing all
the default aliases for builtin commands.

Add docstring comments for all the incant function throughout the
anthology, documenting what each function does, and an example of it's
shell command.