Updated dbus API. Now it sends a signal with every capture, it may
be captureFailed or a captureTaken which contains the raw image
bytes in png format. You have to add an id to the screenshot calls
so it will be returned as a way to know the origin of the signal.
- new imgur upload interface.
- rework for a better code structure. It still needs another change separating the Controller from the code dedicated to export data to the system.
- created the concept of "worker", component used to do some work based on a screenshot.
