Port tools/check_character_names.py to Python 3

[jdufresne]

• Use print() function, not statement
• Replace chr() with unichr()
• Convert tabs to spaces to follow PEP8
• Replace variable all with total to avoid shadowing the builtin
• Compile the regular expression once to avoid the overhead in the loop
• Use a context manager to always close the "NamesList.txt" file