Allocate memory when a character set is requested:

- For simple character sets: from_uni convertion table.
- For UCA: alternative weight arrays.
Use mbminlen instead of MY_CS_NONTEXT

strings/ctype-bin.c

@@ -333,6 +333,7 @@ skip:
 
 MY_COLLATION_HANDLER my_collation_8bit_bin_handler =
 {
+    NULL,			/* init */
     my_strnncoll_binary,
     my_strnncoll_binary,
     my_strnxfrm_bin,
@@ -346,6 +347,7 @@ MY_COLLATION_HANDLER my_collation_8bit_bin_handler =
 
 static MY_CHARSET_HANDLER my_charset_handler=
 {
+    NULL,			/* init */
     NULL,			/* ismbchar      */
     my_mbcharlen_8bit,		/* mbcharlen     */
     my_numchars_8bit,