Typo in comments fixed.

Typo in comments fixed.
(Qccl_program_idx, Qunification_table, Qunification_table_id): New
variables.
(syms_of_ccl): Initialize and staticpro them.
(CCL_ReadMultibyteChar2): Macro name changed from
CCL_ReadMultibyteCharacter.
(CCL_WriteMultibyteChar2): Macro name changed from
CCL_WriteMultibyteChar2.
(CCL_
(MAX_TABLE_SET_LEVEL): New macro.
(tr_stack): New type.
(translate_stack, translate_stack_pointer): New variables.
(PUSH_TRANSLATE_STACK, POP_TRANSLATE_STACK): New macros.
(ccl_driver): Adjusted for the above changes.
(resolve_symbol_ccl_program): New function.
(Fccl_execute): The arg CCL-PROGRAM can be a symbol of CCL
program.  If CCL-PRGRAM is a vector, convert symbols in it to ID
numbers by resolve_symbol_ccl_program.
(Fccl_execute_on_string): Likewise.
(Fregister_ccl_program): If the arg CCL-PRGRAM is a vector,
convert symbols in it to ID numbers by resolve_symbol_ccl_program.