Implement chat messages, mtproto typings and so on

[zerobias]

• Implemented mesage slice loading. Use method api/chats loadSliceRange. It can load various slices ov history, helpful for continious history loading.

• Implemented redux fields chats (possibly should named as dialogs) and users

  • chats. Main dialogs cache, reacts to slice loading, store every dialog messages in normalized form
  • users. Draft realisation. Automatically updates if loaded slice contains unknown users.

• Implemented chat message component. "Dumb" message component also created in Chat folder, because it seems to me that in the future Chat component will become container, and its was better to debug when all child components was located in the same folder.

• Added Mtproto typings. Its really necessary when anybody will add typings to api actions, because almost all api actions begins with server response invoking.

• Moved complex thunk actions out from redux/modules. This dir contains sub-reducers composed to redux state. Possibly it should named as redux/state or redux/reducers with current reducers.ts as index.ts file.

• Css styling helper classes in helpers/classes

• DC_SERVER env trim

[goodmind]

Roadmap Updates

• [ ] Mapped MTProto types (https://goo.gl/JmBEwO)
• [x] R.T and R.F

[zerobias]

R.T and R.F are already implemented at https://github.com/goodmind/treact/pull/8/commits/d4e73154617f49a1b16974b6a0d2ff4a0b5428c5