major overhaul

- new feature: distance measures for deleted and inserted lines
- some documentation
- some adjustments
Revert "major overhaul"

This reverts commit b5db2fa65e3c0077227697c970207cc4abcea3ce.
Merge branch 'going-for-version-0.1.2' of https://github.com/petermeissner/diffr into going-for-version-0.1.2

Conflicts:
	README.md