Get rid of .offset() undefined error

Been getting an error because $form was empty, when switching between newest or
recently active topics. That was because when setting up editors, it finds
textarea nodes. Textarea nodes exist initially, but makeContentInteractive
turns them into inputs. So we'd init the editors, but by the time it wants to
fetch the textarea's parent form, they're no longer there because we've turned
the textareas into input fields.
This moves the editor init code until after makeContentInteractive has been
called for real.

Change-Id: Ia29c9ed0f839f33f6778ee2581bcd735a0cc4291
Merge "Get rid of .offset() undefined error"