Rewritten tie code: great

[Steve D]

Most of the ties placed by the default behavior of the newly 
rewritten tie code look great, as shown in the regression tests 
for tie-chord.ly:

http://www.lilypond.org/doc/v2.7/input/regression/out-www/collated-files.html

It is so nice to have this aspect of LilyPond improved. Thank you 
Han-Wen.

In addition, it is satisfying to be able to manually format ties 
in some of the extreme cases (multiple intervals of a second 
spaced closely within a chord, etc.).

I admit that I am a little confused about the newly implemented 
manual tie configuration, as exemplified by:

\override TieColumn #'tie-configuration =
#'((0 . -1)  (2 . -1) (5.5 . 1) (7 . 1))
 <b d f g> ~ <b d f g>

In each pair of parameters following the "#'tie-configuration =" 
I assume that the second parameter represents the direction of 
the tie (-1 for a downward arc and 1 for an upward arc), and I 
assume that the first parameter represents the vertical location 
of each tie, but I can't figure out exactly what the numbers (0, 
2, 5.5, 7 in the example above) correspond with or refer to.

Anyway, it's wonderful to have this improved functionality.

Steve D
New Mexico, US

P.S. I paid my co-sponsor pledge for the tie rewriting using 
PayPal. Is the use of PayPal now discouraged? (A few messages in 
lilypond-devel seemed to indicate that might be.) If so, what is 
now a preferred method to send donations/sponsorship funds?