Merge pull request #1 from dchaplinsky/master

Import fixes
Data-loading improvements

- fixed data-loading protocol;
- little changes in architecture;
First steps

- fixed next task loading;
- fixed styles for instruction close button;
- next task loads automatically after user close instruction;
Naive lock and frontend improvements

- added naive lock which prevents redundancy
- ugly json-transformation of task delegated to template
- all data about task is available on frontend
Basic stats model

ADD: simple stats model
ADD: readme
ADD: 'unload' event handler to prevent deadlocks for tasks
Removed redundant tasks locking after discussion.