add support for hashtag, remove dependancy on clientID

git-svn-id: https://plugins.svn.wordpress.org/simple-instagram-widget/trunk@899036 b8457f37-d9ea-0310-8a92-e5e31aec5664
add new admin js file

git-svn-id: https://plugins.svn.wordpress.org/simple-instagram-widget/trunk@899038 b8457f37-d9ea-0310-8a92-e5e31aec5664