Clean up code to remove pyflakes errors.

No changes to behavior, just changes to imports, and removing unused variables.
Modify main() script function of bibname

Use the pre-defined name template in the bibstyles/default.py template. But
script needs to be eliminated or moved out of the module in any case.
Add contributor info on git commit msg format.
Add unit tests

Add tests:
 - NameFormatter
 - BibEntry.make_citekey
 - clean up all tests
Add BibEntry method make_citekey()

Move make_entry_citekey in bibadd.py to method of BibEntry in bibfile.py,
refactor to reflect this change. Modify biblabel.py to use new method.

The new make_citekey function uses a slightly simpler label style dictionary.
It appears that the orginal dict format was an attempt to keep the style
definition similar to the styles in bibstuff.bibstyles, but make citation
labels for a BibTex database seems quite separate from producing in-text
citations and references as in the bibstyles subpackage and I did not see the
need for such generalization.

Also fix bibadd.py to remove pyflakes errors
Modify assertions in share.py to allow unicode

Change assertions to not fail on unicode template strings such as those
returned by json.load(). For example isinstance(s, str) is False for s = u'a
string'. Solution: use isinstance(s, bastring).
biblabel.py 2.0.0: add option to read style file

Add option to read citation key style from a json format style file, see
examples/citekey-style.json. Updated script version to 2.0.0