Improvements for meter program

[WolfgangDrescher]

Add support for kern like spines

input.krn:

**kern	**kern	**kern	**kern
*M3/4	*M3/4	*M3/4	*M3/4
4GG	4B	4d	4g
=1	=1	=1	=1
4G	4B	4d	2g
4E	8cL	4e	.
.	8BJ	.	.
4F#	4A	4d	4dd
=2	=2	=2	=2
4G	4G	2d	4.b
4D	4F#	.	.
.	.	.	8a
4E	4G	4B	4g
=3	=3	=3	=3
4C	8cL	8eL	4.g
.	8BJ	8d	.
8BBL	4c	8e	.
8AAJ	.	8f#J	8a
4GG	4d	4g	4b
=4	=4	=4	=4
2D;	2d;	2f#;	2a;
*-	*-	*-	*-

cat input.krn | composite -x | meter -L

Before	After
**kern-comp *M3/4 4eR =1 4eR 8eRL 8eRJ 4eR =2 4eR 8eRL 8eRJ 4eR =3 8eRL 8eRJ 8eRL 8eRJ 4eR =4 2eR *-	**kern-comp **cdata-beat *M3/4 *M3/4 4eR 3 =1 =1 4eR 1 8eRL 2 8eRJ 2+1/2 4eR 3 =2 =2 4eR 1 8eRL 2 8eRJ 2+1/2 4eR 3 =3 =3 8eRL 1 8eRJ 1+1/2 8eRL 2 8eRJ 2+1/2 4eR 3 =4 =4 2eR 1 *- *-

Fix wrong tandem interpretation in tsig spine

Input as above

cat input.krn | extractxx -k $ | meter -t

Before	After
**kern **cdata-beat **cdata-tsig *M3/4 *M3/4 . * *vi:beat: *vi:tsig: 4g 3 3/4 =1 =1 =1 2g 1 3/4 . . . . . . 4dd 3 3/4 =2 =2 =2 4.b 1 3/4 . . . 8a 2+1/2 3/4 4g 3 3/4 =3 =3 =3 4.g 1 3/4 . . . . . . 8a 2+1/2 3/4 4b 3 3/4 =4 =4 =4 2a; 1 3/4 *- *- *-	**kern **cdata-beat **cdata-tsig *M3/4 *M3/4 *M3/4 * *vi:beat: *vi:tsig: 4g 3 3/4 =1 =1 =1 2g 1 3/4 . . . . . . 4dd 3 3/4 =2 =2 =2 4.b 1 3/4 . . . 8a 2+1/2 3/4 4g 3 3/4 =3 =3 =3 4.g 1 3/4 . . . . . . 8a 2+1/2 3/4 4b 3 3/4 =4 =4 =4 2a; 1 3/4 *- *- *-

Improve pickup analysis in the middle of a piece

Marks a measure as a pickup when bardur < tsigdur and the barline token contains || or :?|?!|?:?.

Input: https://github.com/WolfgangDrescher/mendelssohn-choral-works/blob/master/kern/48-6-herbstlied.krn

Measure 40 will be analyzed as a pickup.

Input: https://github.com/WolfgangDrescher/mendelssohn-choral-works/blob/master/kern/59-2-fruehzeitiger-fruehling.krn

Measure 41 will be analyzed as a pickup.

Input: https://github.com/WolfgangDrescher/mendelssohn-choral-works/blob/master/kern/100-1-andenken.krn

Measure 21 will be analyzed as a pickup.