Small string fix
Merge remote-tracking branch 'upstream/master'
Added an extended continuation line, which connects with a matching cont. line in the next F.b. element.

Occasionally required in Baroque scores and in modern figured-bass-like harmonic analysis.
Merge remote-tracking branch 'upstream/master'
fix #19148: Distortion in sound playback after several measures of play
Merge pull request #217 from mgavioli/figured_bass_extended_contin_lines

Figured bass: extended continuation line