Whinepad: Let 0 be defaultValue of rating for a new record

[pedrottimark]

Problem: If you do not click a star when you add a new records, the value of rating is NaN because of parseInt('', 10). JSON.stringify writes NaN as null, therefore toString will fail during some text searches in the next session when the data has been deserialized.

Solution: Delete conditional expression and parseInt at intermediate levels of the component tree so leaf components receive undefined as defaultValue of fields for a new record.

Steps to verify with console pane open in the browser:

1. Given the default record, type z in the search box. Actual and expected result is no records match.
2. Click add and then click Add to add an empty record.
3. Type z in the search box. Actual and expected result is no records match.
4. Type nan in the search box. Unexpected result is the new record matches.
5. Clear the search box, and then refresh the page to cause Whinepad to read the data from storage.
6. Type z in the search box. Unexpected result is TypeError: row[fields[f]] is null

Sorry about the whitespace changes. Atom editor has to make its mark ;)

P.S. Thank you very much for writing React Up & Running! Your previous JavaScript Patterns was super helpful to me too.