Change HTML5QQ.friendsInfo to dict indexed by uin.
So we don't have to traversal the whole friendsInfo to find out the friend.
Now HTML5QQ.friendsInfo = {
	'categories': [
		{'index', 'name', 'sort', 'friends':[#all friends uin in this categories#]},
		#other categories#,
		...
	],
	'friends': #indexed by uin#
	{
		'category', 'flag',
		'face', 'face_flag', 'nick',
		'markname', 'markname_type',
		'is_vip', 'vip_level'
	}
}