#5516 Make tabChordRepeats default for TabStaff

[Thomas Morley]

This code

\version "2.19.83"
\new TabStaff { <e\6> q }

doesn't keep the information about StringNumber.
As documented one needs to do

\new TabStaff \tabChordRepeats { <e\6> q }

The enhancement is to make tabChordRepeats the default for TabStaff.

Davide Kastrup wrote

How? (Automatic) expansion of q happens at scorification time. There
are no contexts at that time and the context definitions may still
change after scorification.

You'd have to move some of the repeat chord expansion business right
into iteration and engraving.

http://lists.gnu.org/archive/html/bug-lilypond/2019-04/msg00029.html