Massive refactoring
add fancify.py (refactor FancyFormatter)
Supply prog argument to argparse
Refactor nodes.py

Minor refactoring in filesystem.py
Fix sterilization in builder.py

Sterilize datetime.date and float.
Change inrecords format

Use '$caption' instead of 'caption, '$date' instead of 'date', etc.
Block hidden files from reviewing

Dot-prefixed files are ignored by 'jeolm --review', if they are not yet
in inrecords.
Allow additional configuration of LaTeX documents

More options are accepted via '$rigid$opt' or '$fluid$opt' dictionaries.
LaTeX document class can be specified with 'class' key, paper size (as
class option) can be specified with 'paper' key, more class options can be
passed with 'class options' key.