Test syntax change in new mojo
fix warning
move donation back to its place
First step towards users support

Place in database to stor use information
WIP - users support

- users can now:
    - register
    - login
    - logout
    - change password
- new explains know about logged user (it's stored in database)
Merge branch 'master' of github.com:depesz/explain.depesz.com