Re: Add a ly:line-thickness callback for scheme, returning the line thickness

[hanwenn]

http://codereview.appspot.com/5073/diff/601/403
File lily/staff-symbol-referencer-scheme.cc (right):

http://codereview.appspot.com/5073/diff/601/403#newcode41
Line 41: LY_DEFINE (ly_line_thickness, "ly:line-thickness",
can you work staff-symbol in the name?

http://codereview.appspot.com/5073/diff/601/403#newcode47
Line 47: Real thickness = g ? Staff_symbol_referencer::line_thickness
(g) : -1;
no need to check here.  You crash if it is not (the LY_ASSERT_SMOB case)

http://codereview.appspot.com/5073