Add autosave for page edits using browser localstorage.

A small JS library sisyphus (originally in [1] with modifications in [2]) is used to autosave the contents of the editForm to browser local storage (save is triggered by any change to form data).

If there is stored data for the form when the user browses to the edit page then a 'restore' button is dispayed that restores the previous state of the form. This state is removed when the user clicks 'save'.

[1] https://github.com/simsalabim/sisyphus
[2] https://github.com/paulcadman/sisyphus

https://bugs.corefiling.com/show_bug.cgi?id=10370
supersedes: https://bugs.corefiling.com/show_bug.cgi?id=5871
Merge remote-tracking branch 'pwc/bug10370'
The footer, including the version number, now floats right so that it
uses less vertical space given the navigation controls on the left.

https://wiki.int.corefiling.com/pdds/RevikiWednesdayAfternoonTesting