Added support for symbol codepage.
Improved handling of undefined codepage characters.

diff --git a/unicode/c_936.c b/unicode/c_936.c
index fefe753..46216ff 100644
--- a/unicode/c_936.c
+++ b/unicode/c_936.c
@@ -37,7 +37,7 @@
     0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
     0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
     0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
-    0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x00ff,
+    0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x003f,
     /* lead byte 81 */
     0x003f, 0x003f, 0x003f, 0x003f, 0x003f, 0x003f, 0x003f, 0x003f,
     0x003f, 0x003f, 0x003f, 0x003f, 0x003f, 0x003f, 0x003f, 0x003f,
@@ -4268,7 +4268,7 @@
     0xa8a4, 0xa8a2, 0x0061, 0x0061, 0x0061, 0x0061, 0x0061, 0x0063,
     0xa8a8, 0xa8a6, 0xa8ba, 0x0065, 0xa8ac, 0xa8aa, 0x0069, 0x0069,
     0x0064, 0x006e, 0xa8b0, 0xa8ae, 0x006f, 0x006f, 0x006f, 0xa1c2,
-    0x006f, 0xa8b4, 0xa8b2, 0x0075, 0xa8b9, 0x0079, 0x003f, 0x00ff,
+    0x006f, 0xa8b4, 0xa8b2, 0x0075, 0xa8b9, 0x0079, 0x003f, 0x0079,
     /* 0x0100 .. 0x01ff */
     0x0041, 0xa8a1, 0x0041, 0x0061, 0x0041, 0x0061, 0x0043, 0x0063,
     0x0043, 0x0063, 0x0043, 0x0063, 0x0043, 0x0063, 0x0044, 0x0064,