review draw_big5_2003.pl and draw_charspace.pl

convert TAB into spaces
update extract_big5.pl: using Zlib to read data file
update extract char from unihan table

now extract_char.pl will extract big5/gb0 char from unihan.txt
extract_big5.pl and extract_gb0.pl are removed
add a function at charutil.pl
move Unihan 5.1.0 table into data/