[fb] Include spine splits for calculating the base pitch

[WolfgangDrescher]

Spine splits should be included when calculating the base pitch of the base track. Currently it can handle chords and always takes the lowest pitch found of a slice.

http://verovio.humdrum.org/?file=beethoven/sonatas/sonata05-2.krn

=60	=60	=60	=60
*^	*	*^	*
24r	4E-	.	(8ccL	4a-X	p
(<24e-LL	.	6 4	.	.	.
24dnJJ)	.	7 5	.	.	.
24re	.	.	8ee-	.	.
(<24d-LL	.	2 5	.	.	.
24cJJ)	.	3 6	.	.	.
24r	4E-	.	8dd-	4g	.
(24B-LL	.	3 6	.	.	.
24cJJ)	.	2 5	.	.	.
24rc	.	.	8b-J)	.	.
(<24d-LL	.	6 4	.	.	.
24GJJ)	.	3 8	.	.	.

[WolfgangDrescher]

Fixed in d7f1db7.

[WolfgangDrescher]

There are still some edge cases when there is a rest in the primary token followed by a spine split.

fb -c -a

In this example, this becomes even more obvious (measue 73):

=71	=71	=71	=71
8d- 8e-L	4 2	[4gg	pp
8d- 8e-	4 2	.	.
8d- 8e-	4 2	(8ggSsSL]	.
8d- 8e-J	5 2	16.aa-XL	.
.	6 2	32bb-JJk)	.
=72	=72	=72	=72
8c 8e-L	7 3	(8bb-	.
8c 8e-	6 3	4aa-	.
8c 8e-	6 3	.	.
8c 8e-J	n6 3	8aan)	.
=73	=73	=73	=73
*^	*	*	*
4.ryy	8G 8d- 8e-L	.	[4bb-	.
.	8G 8d- 8e-	.	.	.
.	8G 8d- 8e-)	.	(8bb-SSSL]	.
(16.cLL	8G >8e-J	4 6 4	16.cccnL	.
32B-JJk)	.	5 6 3	32ddd-JJk)	.
*v	*v	*	*	*
!!LO:LB:g=original

[WolfgangDrescher]

Fixed in f79f52c.

[WolfgangDrescher]

Somewhat related is bc7d0d7. Spine splits are now handled when using --lowest.