read csv and make dictionary
usage :
- ret = CSV2Dict.do('unit.csv','unit_id') # unique key csv , filename 'unit.csv' , key name is 'unit_id'
- unit_level = CSV2Dict.do_multi_key('upgrade.csv',('unit_id','level')) # multi key csv , key must tuple.
- if you want make key int , set make_key_int=True
- if header is [] , CSV's first row is header , you can fill custom header , set header=['foo','xxx','aaa']
- you can make custom do function.