Add new verticalalignment option 'cap' for OpenGL plotting. * libinterp/interp-core/txt-eng-ft.cc(ft_render::text_to_pixels): Implement new 'cap' vertical alignment which is glyph_max_height - glyph_descender_height. This approximates height of a capital letter. * libinterp/interpfcn/graphics.cc (text::properties::update_text_extent): Add 'cap' to if/else if/ tree checking possible verticalalignment options.

--- a/libinterp/interp-core/txt-eng-ft.cc	Wed Mar 06 12:14:11 2013 -0800
+++ b/libinterp/interp-core/txt-eng-ft.cc	Wed Mar 06 15:10:22 2013 -0800
@@ -650,6 +650,7 @@
     case 1: box(1) = -box(3)/2; break;
     case 2: box(1) = -box(3); break;
     case 3: break;
+    case 4: box(1) = -box(3)-box(1); break;
     }
 
   switch (rot_mode)