2to3 some more files; remove cjklib.util.UnicodeCSVFileIterator

cjklib/build/builder.py
cjklib/build/cli.py
- 2to3.

cjklib/util.py
- Functionality of UnicodeCSVFileIterator is provided by csv.reader.

cjklib/data/charactershanghaineseipa.csv
- Replace \t with , as a separator in this file to align with all
  others in this directory.
Replace a custom warn() method with built-in logging module.
Skip an unnecessary decode