Added WhichBrowser library

git-svn-id: https://plugins.svn.wordpress.org/duracelltomi-google-tag-manager/trunk@849064 b8457f37-d9ea-0310-8a92-e5e31aec5664
Added blacklist/whitelist feature

git-svn-id: https://plugins.svn.wordpress.org/duracelltomi-google-tag-manager/trunk@849065 b8457f37-d9ea-0310-8a92-e5e31aec5664