Tested up to WordPress 4.0 and added plugin icons for the new plugin installer

git-svn-id: https://plugins.svn.wordpress.org/svg-support/trunk@981025 b8457f37-d9ea-0310-8a92-e5e31aec5664
change trunk readme stable tag and main file version to 2.1.7

git-svn-id: https://plugins.svn.wordpress.org/svg-support/trunk@981083 b8457f37-d9ea-0310-8a92-e5e31aec5664