Implement bar-line markup command
Input is a string which may contain every of "[]{}S|.:!;". Output is a vertical centered bar line, like the ones for the bar- command in music. Additionally brace bar lines are coded. All types scale with fontsize. Most with height, apart from: Bracket bar line: The bracket-tips are not scaled with height. Mimicking SystemStartBracket. Neither segno bar line, in order to be inline with the behaviour of the segno bar line in music. Parameter like hair/thick-thickness and kern are adjustable. Dashed and dotted have an customizable amount of dashes resp. dots.
Closes #3164 (closed)