Signed-off-by: Mimoja <git@mimoja.de>

Use dbf.finalrewind.org instead of bahn.expert

See merge request !10

- changes the API endpoint
- adds extra handling for RB33
- replaces strings which would produce escape codes with raw strings
- adds custom useragent to web requests

Use raw strings to avoid invalid escape sequences

Closes #7

See merge request !9

Remove more broken/dead MQTT code

See merge request !8

Recent versions of Python (tested with 3.12) print the following syntax
warnings. To avoid them, use the r'' raw string syntax in strings that (may)
contain a backslash that is not supposed to be an escape sequence.

$ ./busdisplay.py
busdisplay.py:74: SyntaxWarning: invalid escape sequence '\-'
  sp+' _|--/~\------/~\-+  |__________________| |__________________| |__________________|'+sp,
busdisplay.py:75: SyntaxWarning: invalid escape sequence '\_'
  sp+'//// \_/      \_/       (O)        (O)       (O)        (O)     (O)        (O)sp   '+sp
busdisplay.py:87: SyntaxWarning: invalid escape sequence '\s'
  sp = re.split('\s+|(?=\()|(?<=\))', text)
busdisplay.py:296: SyntaxWarning: invalid escape sequence '\_'
  self.block.set_rows([(None, 'K1', 'Zyge', '¯\_(ü)_/¯')])

Fixes: 678c1d8c ("Remove unused MQTT code")

Misc.

See merge request !7

As far as I can tell:

- The period (.) glyph is changed from a diamond shape to a single dot
- The zero (0) glyph gets a slash
- The T glyph gets a slightly wider horizontal line

Fixes: 25502c64 ("Schützenstraße")

Make project REUSE v3-compliant

See merge request !6

:)