Follow recent pathlib.py (pep428 branch) changes
Add --review option to jeolm build, enhance review

Review diff output is now splitted by metapaths, and shown in ndiff
format rather that unified diff.
Some refactoring is introduced by this commit.
refactor commands.py and diffprint.py

Enhance review diff output
Refactor spell checker

Along with monir refactoring of diff/log output.
Allow manner to include another manner

Along with some FlagSet and Records refactoring.
Enable score box in test documents