text interleaves

[Keith OHara]

Starting with 2.17.2 or so, text is placed as closely as the detailed shapes
will allow.  There is a regression test ‘text-script-vertical-skylines.ly’
checking for this behavior but I have seen no example where we want text so
closely spaced to other objects.

 {\tempo "Adagio" r4 b'4^"sadly" r2 }  
% Workaround with spaces "Adagio   "

% Workaround with \override MetronomeMark #'vertical-skylines = #'()
%                 \override TextScript #'vertical-skylines = #'()

I request that the 2.16 behavior be the default, letting people who want the
close spacing apply an override.