The function `adjust-character-encoding` in init-cl.lisp forces UTF-8
encoding on several lisps, so make a note of it here that for many
lisps we don't need to check the external format in use.
Fix warnings about undefined function display2d-unicode-enabled
Move the function `display2d-unicode-enabled` from init-cl.lisp to
displa.lisp to fix the warnings that `display2d-unicode-enabled` is
undefined. Also move the definition of `$display2d_unicode` here as well.
Remove adding ccl character names and some doc changes
Since we don't need names for the unicode characters for drawing
boxes (and related chars), get rid of the code for ccl that added the
character names.
Minor indentation change for adding the feature
`:lisp-unicode-capable` to make it easier to see we're pushing stuff.
Finally, fix comment that said `maxima-unicode-enabled`. I think's
it's `display2d-unicode-enabled` now.
Fix warnings about undefined vars for unicode chars
Move the defvars for the unicode box characters earlier in the file so
we don't get warnings about undefined variables.
Also fix one warning from `d-box-unicode` that `dmstr` is unknown and
assumed to be global. We just need to make `dmstr` an `&aux` variable
like the other functions that use `dmstr`. (Should we have just used
a `let` instead?)
