Make showmissing smarter

Try not to check thetvdb unless the show is near a known broadcast date.
Make changes to the info output

- Add synopsis to info
   eg: tv info --synopsis
- Can now specify a show name with info
   eg: tv info Dominion
Remove 'smart showmissing' changes from master and leave them in the
smart_showmissing branch

Due to some accidental commits things got mixed up.
When getting info for one show, show all data
Bug fix

Ignore season 0 episodes since they are not real shows
Remove --db-file DB-FILE option

This option is really only for development and debugging purposes so
it shouldn't be seen by a user.  It just adds noise to the help text.

The code still tests for the option incase it needs to be added in the
future.
Add a nameFilter method to the AllSeries object

The AllSeries object can now return a list of shows filtered by a
name or part of a name.

info, calendar, and download now make use of this method.
Update README.org

Update readme for new options and modify the help text.