not raise error if receive warning. add "file", "xy" to NEED_QUOTE. add "for", "smooth" to NONEED_QUOTE. fix OptArg.quote, OptArg.squote: quote only if String. fix parse_kv: normal join if non-string array. fix parse_kv: parse "label:true". fix parse_kv: join with ":" if keyword "every".
not raise error if receive warning.
add "file", "xy" to NEED_QUOTE.
add "for", "smooth" to NONEED_QUOTE.
fix OptArg.quote, OptArg.squote: quote only if String.
fix parse_kv: normal join if non-string array.
fix parse_kv: parse "label:true".
fix parse_kv: join with ":" if keyword "every".

ruby-numo/gnuplot