Add docstrings for most public API methods.
Add better initialization logic.
Merge branch 'master' of https://github.com/JustusW/BetterOrderedDict into JustusW-master

Resolved a conflict related to my adding docstrings.

Conflicts:
	better_od/core.py
Add setup.cfg.
Update README.md.
Smarter reorder_keys implementation.

Now using sets for correct key membership checks.
Make the initial usage example clearer.
Merge branch 'master' of https://github.com/JustusW/BetterOrderedDict into JustusW-master

Resolve merge conflicts.

Conflicts:
	better_od/core.py
Merge branch 'JustusW-master'

Using Justus' changes.
Conflicts:
	better_od/core.py
Merge pull request #1 from therealfakemoot/master

.