Add support for posting last week's entry

[WardBenjamin]

I had a partial entry saved in WhatGotDone for last week, and I was going to wrap it up and post this morning.

I'd like to be able to:

• access that partial entry from last week
• post an entry backdated by at least 2-3 days (that way you can post until say Monday for the previous week)

[mtlynch]

Thanks for reporting this!

I'm currently tracking this in #318.

The workaround is to edit this week's entry and manually change the date in the URL to the week you want to edit.

[WardBenjamin]

Thanks, totally missed that!