Update to commit 477146b from git@github.com:wp-stream/stream.git

Includes the following commit(s):

commit 477146bfce0292c927f4402742bddb3274dbcb55
Author: Frankie Jarrett <frankie@x-team.com>

    Updating readme

M	readme.md

commit bf94b7aa177d3e354d1d10527a0b9568d93b2789
Author: Frankie Jarrett <frankie@x-team.com>

    Adding new assets and tested up to for WP 4.0

M	assets/banner-1544x500.png
M	assets/banner-772x250.png
A	assets/icon-128x128.png
A	assets/icon-256x256.png
A	assets/icon.svg
M	readme.txt


git-svn-id: https://plugins.svn.wordpress.org/stream/trunk@979889 b8457f37-d9ea-0310-8a92-e5e31aec5664