Minor whitespace change.
Added server-side validation to prevent blank story titles.

Resolves issue #12.
Added title and content validation to `new.jsp`.

The form on `new.jsp` can no longer be submitted if either:

1. the `title` field is blank, or
2. the `content` field is blank.

The `option` fields can be blank because a page with no options is
treated as a dead end, which is a valid page.
The form on `write.jsp` can no longer be submitted if the `content`
field is blank.

The `option` fields can be blank because a page with no options is
treated as a dead end, which is a valid page.
Removed debugging messages.
Updated datastore indexes.