Bugfixes & Anti-Spam Update

Nothing exciting, this time. Just small bug fixes and a response message editor for activated self-joined groups (like Health1 and Red Pill).

* There's also another anti-spam layer and a few tweaks to the authoring tools.

* "What's New" now shows posts from the last week, instead of only since your last login (this will be modified further in #98).

* Updates to post batch processor.

* Post read time bug fixed.

* Post update markers added for clarity on changed articles.

There will be a few more simple updates in this version, coming a bit later.