* Adding visual captchas for register and login.
* Adding audio wav file for Captcha using espeak.
* Lots of captcha fixes.
- Removed login captchas.
- Added settings to disable captchas, and change difficulty.
- Captchas can only be checked / used once, front end gives a new one on
failure.
- Added front end button for regenerating captcha.
- Added a disabled / pause button audio playing.
* Some more fixes.
- Adding front_end_dir to settings.
- Adding unit test for PasswordResetRequest encryption.
- Readme points to lemmy.hjson
- Fixing docker prod, dev, and ansible builds.
- Removing redundant env files, as all config is now in a single file.
- Some formatting fixes.