Get rid of main loop blocking

[garretraziel]

Using blocked, you quickly discover that main loop is blocked pretty often - only starting qubie and loading two pages shows:

[garret@blanka qb]$ nodemon server.js 
7 Dec 12:20:43 - [nodemon] v1.2.1
7 Dec 12:20:43 - [nodemon] to restart at any time, enter `rs`
7 Dec 12:20:43 - [nodemon] watching: *.*
7 Dec 12:20:43 - [nodemon] starting `node server.js`
App is running on port 8080
blocked for 15ms
blocked for 334ms
blocked for 106ms
blocked for 27ms

Problem can be, generally, JSON parsing (so there will surely be problem in drawdb.js) and other CPU-heavy tasks. Go through the code and check all actions to be non-blocking.