Map Big5-HKSCS to Big5

Note this is a naive mapping only, no extra characters are added.

To really support HKSCS, please refer to:  
http://www.ogcio.gov.hk/en/business/tech_promotion/ccli/hkscs/
http://www.ogcio.gov.hk/en/business/tech_promotion/ccli/terms/doc/New2003cmp_2008.txt