fix typo
fixed issue related to https://jira.mongodb.org/browse/SERVER-14623
Merge pull request #2 from jimoleary/master

fixed issue related to https://jira.mongodb.org/browse/SERVER-14623
- Check date is within acceptable range to insert in ObjectId
- Use 0 as default value if user deletes value in input fields
- Small cosmetic change
nicer double-sided arrow