2.3.21 vertical spacing too loose (Regression vs. 2.3.6/2.3.16, possibly 2.2.x)

[Matthias Neeracher]

It seems that around the time the 2.3 series switched back to the TeX 
backend, inter-line spacing of songs with lyrics increased 
substantially and, IMHO, for the worse.

As an example, output for the following song:

http://homepage.mac.com/neeracher/lilypond-bugs/oneandonly.ly

evolved as follows during the 2.3 series:

In 2.3.6 (An early 2.3 release with TeX backend I randomly picked), the 
composer name was too close to the music, but otherwise the spacing was 
fine:

http://homepage.mac.com/neeracher/lilypond-bugs/oneandonly-2_3_6.pdf

In 2.3.16 (I think the last release with the postscript backend), the 
spacing was a little bit wider, but the composer name looked much 
better:

http://homepage.mac.com/neeracher/lilypond-bugs/oneandonly-2_3_16.pdf

However, in 2.3.21, the spacing is MUCH wider (too wide IMHO), and the 
last system runs into the "Engraved by Lilypond" tag:

http://homepage.mac.com/neeracher/lilypond-bugs/oneandonly-2_3_21.pdf

This new spacing seems to have been introduced in 2.3.18, which I 
believe is the first release that went back to the TeX backend. Was the 
spacing change deliberate or accidental?

Matthias