hi, mate.
thanks for you job. use your plugin on a project and have fun )
I've added peace of code for starring of repositories here - ssergienko@76f6b51
don't know why so many changes are displaying, I've just added few lines.
the peace of code is:

// starring
this.isStarred = function(owner, repo, cb) {
_request("GET", "/user/starred/" + owner + '/' + repo, null, function(err,res) {
cb(err,res);
});
};
this.star = function(owner, repo, cb) {
_request("PUT", "/user/starred/" + owner + '/' + repo, null, function(err,res) {
cb(err,res);
});
};
this.unstar = function(owner, repo, cb) {
_request("DELETE", "/user/starred/" + owner + '/' + repo, null, function(err,res) {
cb(err,res);
});
};

hope it'll help

PS: fixed bug with "var btoa". now it works

thanks,
Serge