(create_process, Fopen_network_stream): Typo in indexes

(create_process, Fopen_network_stream): Typo in indexes
of array proc_encode_coding_system fixed.
Remove prefix "coding-system-" from coding system symbol names.
(encode_coding) : Fix typo ("=" -> "==").
(detect_coding_iso2022): Detect coding-category-iso-8-2
more precisely.
(ENCODE_RESET_PLANE_AND_REGISTER): Argument `eol' is
deleted.  Don't call ENCODE_DESIGNATION if nothing designated
initially.
(encode_designation_at_bol) New function.
(encode_coding_iso2022): Handle CODING_FLAG_ISO_INIT_AT_BOL and
CODING_FLAG_ISO_DESIGNATE_AT_BOL.
(setup_coding_system): Now, flags of ISO2022 coding
systems contains charsets instead of charset IDs.
(detect_coding_iso2022, decode_coding_iso2022): Make the code
robust against invalid SI and SO.
(Ffind_coding_system, syms_of_coding): Escape newlines in docstring.
(setup_coding_system): Correct setting coding->symbol
and coding->eol_type.  The performance improved.