add support for cloudflare captcha

[chayleaf]

I simply extended the login activity to save all cookies instead of just session id, and if there's a clearly invalid response that seems like it's cloudflare it opens the login activity (but uses main site url, not login page url), and then quits when an image from the main site is requested

[Kinuseka]

built the apk, passed the cloudflare. This patch will work, one issue is the app is stuck on japanese language and will crash if you try to change it

[chayleaf]

@Kinuseka I haven't touched anything related to languages, it was like that all along in-tree