changed handlebars "avatar" helper to "personImage"; added home button to interaction pane (only when sneaky -- needs further investigating on getting it showing up when the interaction pane is invoked); minor css tweaks.

Revert "don't show nsfw posts without a shield in the viewer"

This reverts commit 722116ce.

make sneaky passive by default.  this fixes the bug where a user would like something when the interaction pane is active and the sneaky would show up when the feedback view was re-rendered.

don't render page-viewer twice; last_post should actually get the last post posted, not the first one

phasing out app.user() for app.currentUser