Adds tick mark to scripts (issue 6568055)

[PhilEHolmes]

Reviewers: lemzwerg, janek, Graham Percival,

Message:
Please review

Description:
As it says. A tick mark is a very common way of indicating a breath in
vocal music, but we have no good glyph for this.  This is an attempt to
create one.

Please review this at http://codereview.appspot.com/6568055/

Affected files:
  M mf/feta-scripts.mf


Index: mf/feta-scripts.mf
diff --git a/mf/feta-scripts.mf b/mf/feta-scripts.mf
index  
83859dbe66fc2b4af51bd7bf63947d9700db6913..89ccc25370fa58c9d23e436dc4698630e2874a57  
100644
--- a/mf/feta-scripts.mf
+++ b/mf/feta-scripts.mf
@@ -1736,8 +1736,49 @@ fet_beginchar ("Straight  
caesura", "caesura.straight");
        labels(1a, 1b, 2a, 2b, 3a, 3b, 4a, 4b);
 fet_endchar;

+% A tick character to use instead of a comma or caesura as a breath mark,
+% Very common in vocal notation

-fet_beginchar ("snap pizzicato (Bartok pizzicato)", "snappizzicato");
+fet_beginchar ("Tick mark", "tickmark");
+       save end_rad, bot_rad, pat, y_off;
+       end_rad = linethickness/2;
+       bot_rad = linethickness;
+       path pat;
+
+       y_off# := 0.2 staff_space#;
+       define_pixels (y_off);
+
+       pickup pencircle scaled end_rad;
+
+       lft x1 = 0;
+       y1 = 0.8 staff_space + y_off;
+
+       x2 = 0.6 staff_space;
+       y2l = 0  + y_off;
+
+       top rt z3 = (1.7 staff_space, 1.7 staff_space + y_off);
+       z4 = (0, staff_space + y_off);
+
+       penpos2(0.4 staff_space, 90);
+       penpos3(end_rad, angle(z4-z3)+90);
+       penpos1(end_rad, angle(z2-z1)+90);
+
+       pat = z1r..top z1..z1l{z2-z1}
+                       ..{z2-(z1+(0.3 staff_space,0))}z2l+(-bot_rad, bot_rad)
+                         ..z2l..z2l+(bot_rad, bot_rad){z3-(0.6 staff_space, 
0)-z2}
+                       ..{z3-z4}z3r..rt z3..{z4-z3}z3l
+                       ..{z2-(z3-(0.6 staff_space,0))}rt z2r..{z1-z2}lft 
z2r{z1-z2}
+                       ..cycle;
+       fill pat;
+
+       set_char_box (0, 1.7 staff_space# + epsilon,
+               0, y_off# + 1.7 staff_space#);
+
+
+       penlabels (1,2,3,4);
+fet_endchar;
+
+fet_beginchar ("snap pizzicato (Bartok pizzicato)", "snappizzicat");
        save height, width, thickness, superness;

        height# = 4/15 staffsize#;