Improve ParaFrame Debugging

[rndsrc]

When the data set is large and the data structure is complicated, it becomes non-trivial to write the correct python format-string for hallmark.ParaFrame to parse parameter dataframe. In some cases, a single typo can cause python to create very long list of error messages that are difficult to debug.

The only debugging tool we have now is the debug keyword in hallmark.ParaFrame. By setting it to True, i.e.,

pf = ParaFrame("data/a_{a:d}/b_{b:d}.txt", debug=True)

ParaFrame would print out its parsing logic and the number of matches. See In [11] in hallmark/demos/ParaFrame.ipynb as an example.

However, this feature is very limited. I hope to have at least the following improvements:

1. Better description of what is printed and how can they be used to construct correct format-strings.
2. Number of files that are not matched by the format-string in a directory, and/or an option to print out these files.
3. An command line tool that help doing format-string debugging interactively.

[rndsrc]

When building a command line tool that helps format-string debugging (i.e., improvement #3 above), I suggest:

1. Use entry_points to organize/install the script. See fadge as an example: entry_points setup in setup.py and the actual script.
2. Use click to parse command line options, e.g., see fadge's usage.