Clean up setting saving.

Rather than saving only those settings specified explicitly in
$SettingGroups, check $_REQUEST for all settings listed in
$SettingList.
Actually save response and review preference instructions.

DERP
Screw the pcPaper column.

Tags are clearly better.
ContactInfo gains a `data` field, to be JSON.
Accept <h2>.
Support a clickthrough license for the submissions page.
Message system improvements.

And actually save 0 as a response word limit.