Industrialization: removed explicit api from vk, crawlers as functions, gentle exceptions and logs

* config.json: new name for runtime.json
* config.py: added logging facilities
* config.py: replaced __data with __defaults
* pool.py: fixed bug of always non-equal sets of workers (added __eq__)
* pool.py: fixed bug of joining not started threads
* pool.py: more gentle exception mechanism
* vk.py: removed explicit api definition, any call is avl from client's
code
* vk.py: added refresh method, called by pool
* vk.py: call_throttler period is now can be changed dynamically in
config.json
* vk.py: new wrapper users_get_unlim to hide the implementation of
splitted calls of users.get
* vk.py: more gentle exception handling, including vk errors in
responses
* crawlers_new/crawlers_main.py: all (3) crawlers have been migrated
into simplified form

TODO: add mongodb dump of json objects directly from vk module