* Fixed a bug in StringMatcher.StringMatcher.get_matching_blocks /
extract_editops for Python 3; now allow only `str` editops on
both Python 2 and Python 3, for simpler and working code.
* Added documentation in the source distribution and in GIT
* Fixed the package layout: renamed the .so/.dll to _levenshtein,
and made it reside inside a package, along with the StringMatcher
class.
* Fixed spelling errors.