fixed & improved "dragging"
wrap dragging instructions to $.each… callback
added $.flags and $.registerFlag to create non-writable (constants) values
new functions: registerEvent, Event, callObservers
improved "on" method and register new bit flags for this method
rebuilt "off" method for use custom events
old mouseenter/mouseleave events were adjusted to new custom events model
increased version to 0.2.1 `Escolar`
Merge pull request #12 from tsapeta/0.2.x

merge 0.2.x (0.2.1 `Escolar`)