Merge pull request #5 from wangxiao/master

[feature] Change sign in to use snappea account.
Merge pull request #6 from wangxiao/master

[bugfix] Sign out and clear account storage, and show the pop window's real height.
[feature] Change account to limbo account.
Merge branch 'master' of https://github.com/wangxiao/ChromeExtension-Photos