Add comment replacement and preview image

Add data channel support detection

Change breakpoint to support Pixel 2 XL

Show mailing list signup with ?list_signup=true

A series of tiny bugfixes

Only play speaker test tone on click

Update nav-mesh component and inflator to support precomputed nav-mesh

Fix the check to see if the pose is the same as last time.

Feature/ui pass for hubs

Add block buttons to the avatars during freeze mode.

Remove action_primary actions from vive triggers.

Add block buttons on avatars that show during freeze mode

Merge branch 'feature/block-box' of ssh://github.com/robertlong/social-vr-demo into feature/block-box