Added test for correct str().
Better str().
Got rid of access methods.
Merge remote-tracking branch 'origin/master' into partial-versions-improvement

* origin/master:
  Fixed None in partial versions + version bump
Removed or 0's.

I caused tests to fail.
Added shorthand test.
Enabled shorthand use.
Less duplication in __init__().
Updated README to reflect changes.
Added test for parsing a partial version.
Added parsing of partial versions.
Added * as a partial wildcard.
Merge pull request #8 from cknv/partial-versions-improvement

Partial versions improvement