Fix undefined owner name

Signed-off-by: Max Fierke <max@maxfierke.com>
Show avatar of posting user along with message

Signed-off-by: Max Fierke <max@maxfierke.com>
Add GitHub's gravatar to github post-receive hook messages

Signed-off-by: Max Fierke <max@maxfierke.com>
Tweak .avatar classed elements display

Signed-off-by: Max Fierke <max@maxfierke.com>