Description
 (I hope it's not a duplicate, I searched for open issues).
 Every time I open my browser, i have to select a custom server and re-enter its info, and this flow could be improved, if either I could pass the parameters in the URL, or there was a way to remember the home server.
 Steps to reproduce
  - Open riot.im/app
  - Enter settings
  - Close browser
  - Reopen browser
  - goto 1
  
 Version information
  - Platform: web
  - Browser: Firefox, nightly
  - OS: Linux
  - URL: riot.im/app