removed the wc program requirement.

[petedv]

If done directly in python it is not OS dependent

[kmatt]

For near zero startup time, I replaced the line count with the size of the file in bytes as

num_bytes = os.path.getsize(input_filename)

then keep track the total of the line lengths as

bytes += len(line)

and calculate progress as

percentage_done = bytes / num_bytes
...
logging.write("\rLine %i (%.2f%%) [%s tables] [%s inserts] [ETA: %i min %i sec]"

I let my fork get out of sync with the master through multiple commits, otherwise I would put in a PR