fix #327 - blank detail view body
show help links at login (as links)
move toasts to the bottom
detail tolerates lack of thread
hide empty detail views
add slow validation - closes #342
mismatched validation field
trim the heatmap slightly
move privacy icon to after the username
some reasonable thread padding
use a space in the font icon as default offset
show/hide reply dynamically

This is an attempt to address the extra space the reply button creates
without moving it back to the top (since I feel the reply button goes
well next to the reply count, both thematically and spatially). The
other controls are restored to their former position.

Closes #325.
heatmap should ignore invisible annotations

fixes #332
up/down tabs always scroll to an annotation

closes #232
some contributor doc tweaks
language in contributing
add CLA doc to CONTRIBUTING
broken link syntax
less awkward language
CLA address formatting