Schema update; adding a root folder on user creation
Added bindNull

Also, now mySQL bind(int, const char*) calls bindNull when argument is null
Session support for subscribe API
Small changes

Adding Connection::prepare that can take upper and lower limits
Flushing the log after every line
Fixing status code inside on400()
Subscribe API
Trivial fixes
Column selectors for template programming
JSON renderer
Subscription views
API subscribe
subscription.json