Add visual tests for \overline, \overleftarrow, \overrightarrow, \overleftrightarrow and \overarc
diff --git a/test/visual.html b/test/visual.html
index a5918b5..da926db 100644
--- a/test/visual.html
+++ b/test/visual.html
@@ -212,6 +212,11 @@
 <tr><td><span class="mathquill-static-math">\vec x + \tilde x + \vec A + \tilde A + \vec{abcd} + \tilde{abcd}</span><td><span>\vec x + \tilde x + \vec A + \tilde A + \vec{abcd} + \tilde{abcd}</span>^M

 <tr><td><span class="mathquill-static-math">\int _{\phi =0}^{2\pi }\int _{\theta =0}^{\pi }\int _{r=0}^{\infty }f(r,\theta ,\phi )r^2\sin \theta drd\theta d\phi </span><td><span>\int _{\phi =0}^{2\pi }\int _{\theta =0}^{\pi }\int _{r=0}^{\infty }f(r,\theta ,\phi )r^2\sin \theta drd\theta d\phi </span>

 <tr><td><span class="mathquill-static-math">\int_0^{\frac{\frac{1}{2}}{3}} \int_0^{\frac{1}{\frac{2}{3}}} \int_0^{\frac{1}{\frac{2}{\frac{3}{\frac{4}{5}}}}}</span><td><span>\int_0^{\frac{\frac{1}{2}}{3}} \int_0^{\frac{1}{\frac{2}{3}}} \int_0^{\frac{1}{\frac{2}{\frac{3}{\frac{4}{5}}}}}</span>

+<tr><td><span class="mathquill-static-math">\overline{abc}</span><td><span>\overline{abc}</span>

+<tr><td><span class="mathquill-static-math">\overleftarrow{abc}</span><td><span>\overleftarrow{abc}</span>

+<tr><td><span class="mathquill-static-math">\overrightarrow{abc}</span><td><span>\overrightarrow{abc}</span>

+<tr><td><span class="mathquill-static-math">\overleftrightarrow{abc}</span><td><span>\overleftrightarrow{abc}</span>

+<tr><td><span class="mathquill-static-math">\overarc{abc}</span><td><span>\overarc{abc}</span>

 <tr><td colspan=2><span id="sixes"></span>

 <script>

 $(function() {