DESC
	Usually used for maintain bsdconv inter-mapping tables

INPUT
	DESC	Control characters for bsdconv table format
	EXAMPLE	\n\t,?\\

OUTPUT
	DESC	Properly escaped form for to/BSDCONV-KEYWORD

EXAMPLE
	> printf "測,試\t测,试\n" | bsdconv bsdconv-keyword,utf-8:bsdconv-keyword,bsdconv
	016E2C,018A66	016D4B,018BD5
	> printf "測,試\t测,试\n" | bsdconv bsdconv-keyword,utf-8:bsdconv-keyword,bsdconv | bsdconv bsdconv-keyword,bsdconv:bsdconv-keyword,utf-8
	測,試	测,试
