Merge pull request #1 from vvo/master

fix STATUS_PAUSE => STATUS_PAUSED
v0.3.6
make worker EventEmitter capable
add `status change` and `job complete` events
handle errors before emitting new state
Merge pull request #3 from vvo/events

add simple events on worker
v0.4.0
upgrade lodash to latest
start processing only when status was set

+ start processing after callback was called, so that
if the user wants to pause right after starting, it's available
fix pause and stop methods

this context was not passed
always wait for setStatus commands before calling actions/process
use Date.now() instead of creating Date instances
Merge pull request #4 from vvo/handle-async-operations

Handle async operations
v0.4.1