Add ability to view recently changed items

[monfresh]

Based on the feedback in #305, it could be helpful to have quick access to recently changed items.

To implement, I imagine the following:

• Add "Recently Changed" or "Recent Changes" link to nav bar
• Add page to display those changes, and limit to the last 5 items in each major entity (Organization, Location, Service, Program)
• In this context, recent means in the past x amount of time, where x is configurable, perhaps as multiple links: past day, past week, past month.

[pmackay]

A question related to this - is revisioning of content supported? Has this been discussed?

[monfresh]

Revisioning is not currently supported out of the box. Our Tracking changes to the data in the database Wiki article points to a gem you can use to add this functionality.

[greggish]

@pmackay based on what we hear from users, it's clearly an important feature. I think the SF team may have it on their work list...