add \ae, \AE, \oe, \OE, \o, \O, \ss with unicode support for those characters in text mode (#1030)

metrics/mapping.pl

@@ -64,6 +64,13 @@ $map{cmr10} = {
     0x7E => [0x303,-500,0], # \tilde (combining)
     0x7F => 0xA8,           # \ddot
     0x7F => [0x308,-500,0], # \ddot (combining)
+    0x19 => 0xDF,           # sharp S
+    0x1A => 0xE6,           # ae ligature
+    0x1B => 0x153,          # oe ligature
+    0x1C => 0xF8,           # o with slash
+    0x1D => 0xC6,           # AE ligature
+    0x1E => 0x152,          # OE ligature
+    0x1F => 0xD8,           # O with slash
   ],
 };