Remember user's last location

[isedwards]

Requires #7

The software should remember the last record that each user views for each form (key entry and metadata) and return these records on their next visit.

If the user visits /keyentry/hourly/ then they will either be taken to where they left off or, if they have never visited the key entry form before, they will be taken to a sensible starting point (e.g. default station and element for the current date).