Charm upload series selector.

    QA:
    - make devel/debug/prod;
    - upload a local charm;
    - the inspector should show a series selector;
    - try uploading more local charms with
      different series.
Merge pull request #177 from frankban/series-selector

QA:
- make devel/debug/prod;
- upload a local charm;
- the inspector should show a series selector;
- try uploading more local charms with
  different series.