Javascript UI should record current state in browser location.hash

[Dylan McCall]

In harvest.js, whenever a new list of packages is loaded into the results pane, it may be nice to set location.hash to document the current state being displayed. This way, the browser back / forward buttons can work nicely.

A user could also bookmark a page and go back to it later, and it would show the same query as before.

Note that this does create two methods of storing a page's state.
A user given a URL that has state stored in the hash part (instead of the query string) will NEED Javascript. So, we will still need a more explicit "permalink" mechanism.

This was attempted with the jQuery BBQ plugin in lp:~dylanmccall/harvest/browser-location . That work can probably be salvaged to some extent (it does mostly work, albeit messily), but it looks like harvest.js will need some rethinking for the feature to work well and to be understandable / maintainable in the future.