Add debug mode.
Bugfix:

1. When st 404.html not display user info
2. Display error message is '???'
Merge pull request #27 from xtao/vilya

Add debug mode.
Merge pull request #28 from dongweiming/bugfix_error_html

Bugfix:
modify setup_databases for now
Modify README for correct sql path
Merge pull request #30 from dongweiming/modify_setup_databases

modify setup_databases for now
Update readme about vilya.